diff --git a/libcxx/docs/FeatureTestMacroTable.rst b/libcxx/docs/FeatureTestMacroTable.rst
index bf25b34ba9159..bd73a1d933cb1 100644
--- a/libcxx/docs/FeatureTestMacroTable.rst
+++ b/libcxx/docs/FeatureTestMacroTable.rst
@@ -418,6 +418,8 @@ Status
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_constexpr_algorithms``                         ``202306L``
     ---------------------------------------------------------- -----------------
+    ``__cpp_lib_constexpr_deque``                              ``202502L``
+    ---------------------------------------------------------- -----------------
     ``__cpp_lib_constexpr_new``                                ``202406L``
     ---------------------------------------------------------- -----------------
     ``__cpp_lib_constrained_equality``                         *unimplemented*
diff --git a/libcxx/include/deque b/libcxx/include/deque
index bab76d442a21b..1c19890911b5c 100644
--- a/libcxx/include/deque
+++ b/libcxx/include/deque
@@ -605,7 +605,8 @@ private:
 
 public:
   // construct/copy/destroy:
-  _LIBCPP_HIDE_FROM_ABI deque() _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 deque()
+      _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
       : __start_(0), __size_(0) {
     __annotate_new(0);
   }
@@ -619,19 +620,20 @@ public:
       __alloc_traits::deallocate(__alloc(), *__i, __block_size);
   }
 
-  _LIBCPP_HIDE_FROM_ABI explicit deque(const allocator_type& __a)
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 explicit deque(const allocator_type& __a)
       : __map_(__pointer_allocator(__a)), __start_(0), __size_(0), __alloc_(__a) {
     __annotate_new(0);
   }
 
   explicit _LIBCPP_HIDE_FROM_ABI deque(size_type __n);
 #  if _LIBCPP_STD_VER >= 14
-  explicit _LIBCPP_HIDE_FROM_ABI deque(size_type __n, const _Allocator& __a);
+  explicit _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 deque(size_type __n, const _Allocator& __a);
 #  endif
   _LIBCPP_HIDE_FROM_ABI deque(size_type __n, const value_type& __v);
 
   template <__enable_if_t<__is_allocator<_Allocator>::value, int> = 0>
-  _LIBCPP_HIDE_FROM_ABI deque(size_type __n, const value_type& __v, const allocator_type& __a)
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26
+  deque(size_type __n, const value_type& __v, const allocator_type& __a)
       : __map_(__pointer_allocator(__a)), __start_(0), __size_(0), __alloc_(__a) {
     __annotate_new(0);
     if (__n > 0)
@@ -641,11 +643,12 @@ public:
   template <class _InputIter, __enable_if_t<__has_input_iterator_category<_InputIter>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI deque(_InputIter __f, _InputIter __l);
   template <class _InputIter, __enable_if_t<__has_input_iterator_category<_InputIter>::value, int> = 0>
-  _LIBCPP_HIDE_FROM_ABI deque(_InputIter __f, _InputIter __l, const allocator_type& __a);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 deque(_InputIter __f, _InputIter __l, const allocator_type& __a);
 
 #  if _LIBCPP_STD_VER >= 23
   template <_ContainerCompatibleRange<_Tp> _Range>
-  _LIBCPP_HIDE_FROM_ABI deque(from_range_t, _Range&& __range, const allocator_type& __a = allocator_type())
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26
+  deque(from_range_t, _Range&& __range, const allocator_type& __a = allocator_type())
       : __map_(__pointer_allocator(__a)), __start_(0), __size_(0), __alloc_(__a) {
     if constexpr (ranges::forward_range<_Range> || ranges::sized_range<_Range>) {
       __append_with_size(ranges::begin(__range), ranges::distance(__range));
@@ -658,8 +661,9 @@ public:
   }
 #  endif
 
-  _LIBCPP_HIDE_FROM_ABI deque(const deque& __c);
-  _LIBCPP_HIDE_FROM_ABI deque(const deque& __c, const __type_identity_t<allocator_type>& __a);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 deque(const deque& __c);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26
+  deque(const deque& __c, const __type_identity_t<allocator_type>& __a);
 
   _LIBCPP_HIDE_FROM_ABI deque& operator=(const deque& __c);
 
@@ -667,13 +671,14 @@ public:
   _LIBCPP_HIDE_FROM_ABI deque(initializer_list<value_type> __il);
   _LIBCPP_HIDE_FROM_ABI deque(initializer_list<value_type> __il, const allocator_type& __a);
 
-  _LIBCPP_HIDE_FROM_ABI deque& operator=(initializer_list<value_type> __il) {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 deque& operator=(initializer_list<value_type> __il) {
     assign(__il);
     return *this;
   }
 
-  _LIBCPP_HIDE_FROM_ABI deque(deque&& __c) noexcept(is_nothrow_move_constructible<allocator_type>::value);
-  _LIBCPP_HIDE_FROM_ABI deque(deque&& __c, const __type_identity_t<allocator_type>& __a);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26
+  deque(deque&& __c) noexcept(is_nothrow_move_constructible<allocator_type>::value);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 deque(deque&& __c, const __type_identity_t<allocator_type>& __a);
   _LIBCPP_HIDE_FROM_ABI deque& operator=(deque&& __c) noexcept(
       (__alloc_traits::propagate_on_container_move_assignment::value &&
        is_nothrow_move_assignable<allocator_type>::value) ||
@@ -709,67 +714,81 @@ public:
 
   _LIBCPP_HIDE_FROM_ABI void assign(size_type __n, const value_type& __v);
 
-  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const _NOEXCEPT;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 allocator_type get_allocator() const _NOEXCEPT;
   _LIBCPP_HIDE_FROM_ABI allocator_type& __alloc() _NOEXCEPT { return __alloc_; }
   _LIBCPP_HIDE_FROM_ABI const allocator_type& __alloc() const _NOEXCEPT { return __alloc_; }
 
   // iterators:
 
-  _LIBCPP_HIDE_FROM_ABI iterator begin() _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator begin() _NOEXCEPT {
     __map_pointer __mp = __map_.begin() + __start_ / __block_size;
     return iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
   }
 
-  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator begin() const _NOEXCEPT {
     __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __start_ / __block_size);
     return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
   }
 
-  _LIBCPP_HIDE_FROM_ABI iterator end() _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 iterator end() _NOEXCEPT {
     size_type __p      = size() + __start_;
     __map_pointer __mp = __map_.begin() + __p / __block_size;
     return iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
   }
 
-  _LIBCPP_HIDE_FROM_ABI const_iterator end() const _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator end() const _NOEXCEPT {
     size_type __p            = size() + __start_;
     __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __p / __block_size);
     return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
   }
 
-  _LIBCPP_HIDE_FROM_ABI reverse_iterator rbegin() _NOEXCEPT { return reverse_iterator(end()); }
-  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rbegin() const _NOEXCEPT { return const_reverse_iterator(end()); }
-  _LIBCPP_HIDE_FROM_ABI reverse_iterator rend() _NOEXCEPT { return reverse_iterator(begin()); }
-  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator rend() const _NOEXCEPT { return const_reverse_iterator(begin()); }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 reverse_iterator rbegin() _NOEXCEPT {
+    return reverse_iterator(end());
+  }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator rbegin() const _NOEXCEPT {
+    return const_reverse_iterator(end());
+  }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 reverse_iterator rend() _NOEXCEPT {
+    return reverse_iterator(begin());
+  }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator rend() const _NOEXCEPT {
+    return const_reverse_iterator(begin());
+  }
 
-  _LIBCPP_HIDE_FROM_ABI const_iterator cbegin() const _NOEXCEPT { return begin(); }
-  _LIBCPP_HIDE_FROM_ABI const_iterator cend() const _NOEXCEPT { return end(); }
-  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crbegin() const _NOEXCEPT { return const_reverse_iterator(end()); }
-  _LIBCPP_HIDE_FROM_ABI const_reverse_iterator crend() const _NOEXCEPT { return const_reverse_iterator(begin()); }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator cbegin() const _NOEXCEPT { return begin(); }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_iterator cend() const _NOEXCEPT { return end(); }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator crbegin() const _NOEXCEPT {
+    return const_reverse_iterator(end());
+  }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reverse_iterator crend() const _NOEXCEPT {
+    return const_reverse_iterator(begin());
+  }
 
   // capacity:
-  _LIBCPP_HIDE_FROM_ABI size_type size() const _NOEXCEPT { return __size(); }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 size_type size() const _NOEXCEPT { return __size(); }
 
   _LIBCPP_HIDE_FROM_ABI size_type& __size() _NOEXCEPT { return __size_; }
   _LIBCPP_HIDE_FROM_ABI const size_type& __size() const _NOEXCEPT { return __size_; }
 
-  _LIBCPP_HIDE_FROM_ABI size_type max_size() const _NOEXCEPT {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 size_type max_size() const _NOEXCEPT {
     return std::min<size_type>(__alloc_traits::max_size(__alloc()), numeric_limits<difference_type>::max());
   }
-  _LIBCPP_HIDE_FROM_ABI void resize(size_type __n);
-  _LIBCPP_HIDE_FROM_ABI void resize(size_type __n, const value_type& __v);
-  _LIBCPP_HIDE_FROM_ABI void shrink_to_fit() _NOEXCEPT;
-  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI bool empty() const _NOEXCEPT { return size() == 0; }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void resize(size_type __n);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void resize(size_type __n, const value_type& __v);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void shrink_to_fit() _NOEXCEPT;
+  [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 bool empty() const _NOEXCEPT {
+    return size() == 0;
+  }
 
   // element access:
-  _LIBCPP_HIDE_FROM_ABI reference operator[](size_type __i) _NOEXCEPT;
-  _LIBCPP_HIDE_FROM_ABI const_reference operator[](size_type __i) const _NOEXCEPT;
-  _LIBCPP_HIDE_FROM_ABI reference at(size_type __i);
-  _LIBCPP_HIDE_FROM_ABI const_reference at(size_type __i) const;
-  _LIBCPP_HIDE_FROM_ABI reference front() _NOEXCEPT;
-  _LIBCPP_HIDE_FROM_ABI const_reference front() const _NOEXCEPT;
-  _LIBCPP_HIDE_FROM_ABI reference back() _NOEXCEPT;
-  _LIBCPP_HIDE_FROM_ABI const_reference back() const _NOEXCEPT;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 reference operator[](size_type __i) _NOEXCEPT;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reference operator[](size_type __i) const _NOEXCEPT;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 reference at(size_type __i);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reference at(size_type __i) const;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 reference front() _NOEXCEPT;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reference front() const _NOEXCEPT;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 reference back() _NOEXCEPT;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 const_reference back() const _NOEXCEPT;
 
   // 23.2.2.3 modifiers:
   _LIBCPP_HIDE_FROM_ABI void push_front(const value_type& __v);
@@ -789,8 +808,8 @@ public:
   template <class... _Args>
   _LIBCPP_HIDE_FROM_ABI iterator emplace(const_iterator __p, _Args&&... __args);
 
-  _LIBCPP_HIDE_FROM_ABI void push_front(value_type&& __v);
-  _LIBCPP_HIDE_FROM_ABI void push_back(value_type&& __v);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void push_front(value_type&& __v);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void push_back(value_type&& __v);
 
 #    if _LIBCPP_STD_VER >= 23
   template <_ContainerCompatibleRange<_Tp> _Range>
@@ -1570,7 +1589,7 @@ inline typename deque<_Tp, _Allocator>::const_reference deque<_Tp, _Allocator>::
 }
 
 template <class _Tp, class _Allocator>
-void deque<_Tp, _Allocator>::push_back(const value_type& __v) {
+void _LIBCPP_CONSTEXPR_SINCE_CXX26 deque<_Tp, _Allocator>::push_back(const value_type& __v) {
   allocator_type& __a = __alloc();
   if (__back_spare() == 0)
     __add_back_capacity();
@@ -1658,7 +1677,8 @@ deque<_Tp, _Allocator>::emplace_front(_Args&&... __args) {
 }
 
 template <class _Tp, class _Allocator>
-typename deque<_Tp, _Allocator>::iterator deque<_Tp, _Allocator>::insert(const_iterator __p, value_type&& __v) {
+_LIBCPP_CONSTEXPR_SINCE_CXX26 typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::insert(const_iterator __p, value_type&& __v) {
   size_type __pos     = __p - begin();
   size_type __to_end  = size() - __pos;
   allocator_type& __a = __alloc();
@@ -1755,7 +1775,8 @@ typename deque<_Tp, _Allocator>::iterator deque<_Tp, _Allocator>::emplace(const_
 #  endif // _LIBCPP_CXX03_LANG
 
 template <class _Tp, class _Allocator>
-typename deque<_Tp, _Allocator>::iterator deque<_Tp, _Allocator>::insert(const_iterator __p, const value_type& __v) {
+_LIBCPP_CONSTEXPR_SINCE_CXX26 typename deque<_Tp, _Allocator>::iterator
+deque<_Tp, _Allocator>::insert(const_iterator __p, const value_type& __v) {
   size_type __pos     = __p - begin();
   size_type __to_end  = size() - __pos;
   allocator_type& __a = __alloc();
@@ -1807,7 +1828,7 @@ typename deque<_Tp, _Allocator>::iterator deque<_Tp, _Allocator>::insert(const_i
 }
 
 template <class _Tp, class _Allocator>
-typename deque<_Tp, _Allocator>::iterator
+typename deque<_Tp, _Allocator>::iterator _LIBCPP_CONSTEXPR_SINCE_CXX26
 deque<_Tp, _Allocator>::insert(const_iterator __p, size_type __n, const value_type& __v) {
   size_type __pos     = __p - begin();
   size_type __to_end  = __size() - __pos;
@@ -2543,7 +2564,8 @@ inline void deque<_Tp, _Allocator>::clear() _NOEXCEPT {
 }
 
 template <class _Tp, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI bool operator==(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y) {
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 bool
+operator==(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y) {
   const typename deque<_Tp, _Allocator>::size_type __sz = __x.size();
   return __sz == __y.size() && std::equal(__x.begin(), __x.end(), __y.begin());
 }
@@ -2578,7 +2600,7 @@ inline _LIBCPP_HIDE_FROM_ABI bool operator<=(const deque<_Tp, _Allocator>& __x,
 #  else // _LIBCPP_STD_VER <= 17
 
 template <class _Tp, class _Allocator>
-_LIBCPP_HIDE_FROM_ABI __synth_three_way_result<_Tp>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 __synth_three_way_result<_Tp>
 operator<=>(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y) {
   return std::lexicographical_compare_three_way(__x.begin(), __x.end(), __y.begin(), __y.end(), std::__synth_three_way);
 }
@@ -2586,14 +2608,14 @@ operator<=>(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y
 #  endif // _LIBCPP_STD_VER <= 17
 
 template <class _Tp, class _Allocator>
-inline _LIBCPP_HIDE_FROM_ABI void swap(deque<_Tp, _Allocator>& __x, deque<_Tp, _Allocator>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 void
+swap(deque<_Tp, _Allocator>& __x, deque<_Tp, _Allocator>& __y) _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y))) {
   __x.swap(__y);
 }
 
 #  if _LIBCPP_STD_VER >= 20
 template <class _Tp, class _Allocator, class _Up>
-inline _LIBCPP_HIDE_FROM_ABI typename deque<_Tp, _Allocator>::size_type
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 typename deque<_Tp, _Allocator>::size_type
 erase(deque<_Tp, _Allocator>& __c, const _Up& __v) {
   auto __old_size = __c.size();
   __c.erase(std::remove(__c.begin(), __c.end(), __v), __c.end());
@@ -2601,7 +2623,7 @@ erase(deque<_Tp, _Allocator>& __c, const _Up& __v) {
 }
 
 template <class _Tp, class _Allocator, class _Predicate>
-inline _LIBCPP_HIDE_FROM_ABI typename deque<_Tp, _Allocator>::size_type
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX26 typename deque<_Tp, _Allocator>::size_type
 erase_if(deque<_Tp, _Allocator>& __c, _Predicate __pred) {
   auto __old_size = __c.size();
   __c.erase(std::remove_if(__c.begin(), __c.end(), __pred), __c.end());
diff --git a/libcxx/include/version b/libcxx/include/version
index 0a19ff9ad8187..e451e49fe1a3d 100644
--- a/libcxx/include/version
+++ b/libcxx/include/version
@@ -66,6 +66,7 @@ __cpp_lib_constexpr_bitset                              202207L <bitset>
 __cpp_lib_constexpr_charconv                            202207L <charconv>
 __cpp_lib_constexpr_cmath                               202202L <cmath> <cstdlib>
 __cpp_lib_constexpr_complex                             201711L <complex>
+__cpp_lib_constexpr_deque                               202502L <deque>
 __cpp_lib_constexpr_dynamic_alloc                       201907L <memory>
 __cpp_lib_constexpr_functional                          201907L <functional>
 __cpp_lib_constexpr_iterator                            201811L <iterator>
@@ -539,6 +540,7 @@ __cpp_lib_void_t                                        201411L <type_traits>
 # define __cpp_lib_bitset                               202306L
 # undef  __cpp_lib_constexpr_algorithms
 # define __cpp_lib_constexpr_algorithms                 202306L
+# define __cpp_lib_constexpr_deque                      202502L
 # if !defined(_LIBCPP_ABI_VCRUNTIME)
 #   define __cpp_lib_constexpr_new                      202406L
 # endif
diff --git a/libcxx/test/std/containers/sequences/deque/compare.pass.cpp b/libcxx/test/std/containers/sequences/deque/compare.pass.cpp
index 526e3d38e7dff..25aea88911d82 100644
--- a/libcxx/test/std/containers/sequences/deque/compare.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/compare.pass.cpp
@@ -37,7 +37,7 @@
 
 #include "test_comparisons.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     const std::deque<int> d1, d2;
     assert(testComparisons(d1, d2, true, false));
@@ -113,6 +113,14 @@ int main(int, char**) {
     const std::deque<LessAndEqComp> d2(items2, items2 + 2);
     assert(testComparisons(d1, d2, false, false));
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/compare.three_way.pass.cpp b/libcxx/test/std/containers/sequences/deque/compare.three_way.pass.cpp
index 3d5646a844951..f35ef6081c866 100644
--- a/libcxx/test/std/containers/sequences/deque/compare.three_way.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/compare.three_way.pass.cpp
@@ -18,8 +18,15 @@
 
 #include "test_container_comparisons.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   assert(test_sequence_container_spaceship<std::deque>());
-  // `std::deque` is not constexpr, so no `static_assert` test here.
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.capacity/access.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.capacity/access.pass.cpp
index 294663c5bd356..fa2ab8c2f45b1 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.capacity/access.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.capacity/access.pass.cpp
@@ -47,7 +47,7 @@ C make(int size, int start = 0) {
   return c;
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     typedef std::deque<int> C;
     C c = make<std::deque<int> >(10);
@@ -118,6 +118,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.capacity/empty.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.capacity/empty.pass.cpp
index 5e3a6ec1cea82..cb684a312067b 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.capacity/empty.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.capacity/empty.pass.cpp
@@ -19,7 +19,7 @@
 #include "test_macros.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     typedef std::deque<int> C;
     C c;
@@ -46,6 +46,13 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
   }
 #endif
+  return true;
+}
 
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.capacity/max_size.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.capacity/max_size.pass.cpp
index 39feabe3889b3..8043e8e030114 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.capacity/max_size.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.capacity/max_size.pass.cpp
@@ -19,7 +19,7 @@
 #include "test_allocator.h"
 #include "test_macros.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     typedef limited_allocator<int, 10> A;
     typedef std::deque<int, A> C;
@@ -45,6 +45,14 @@ int main(int, char**) {
     assert(c.max_size() <= alloc_max_size(c.get_allocator()));
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.capacity/resize_size.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.capacity/resize_size.pass.cpp
index 767fe7ae8864e..8bd735a2cedd5 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.capacity/resize_size.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.capacity/resize_size.pass.cpp
@@ -63,7 +63,7 @@ void testN(int start, int N, int M) {
   test(c1, M);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -90,6 +90,14 @@ int main(int, char**) {
           testN<std::deque<int, safe_allocator<int>>>(rng[i], rng[j], rng[k]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.capacity/resize_size_value.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.capacity/resize_size_value.pass.cpp
index 0abd94759a50f..9e1d3ff39e18f 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.capacity/resize_size_value.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.capacity/resize_size_value.pass.cpp
@@ -63,7 +63,7 @@ void testN(int start, int N, int M) {
   test(c1, M, -10);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -91,5 +91,13 @@ int main(int, char**) {
   }
 #endif
 
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.capacity/shrink_to_fit.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.capacity/shrink_to_fit.pass.cpp
index 34eedf8d050b7..fed42d2b691c9 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.capacity/shrink_to_fit.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.capacity/shrink_to_fit.pass.cpp
@@ -50,7 +50,7 @@ void testN(int start, int N) {
   test(c1);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -74,6 +74,14 @@ int main(int, char**) {
         testN<std::deque<int, safe_allocator<int>> >(rng[i], rng[j]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.capacity/size.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.capacity/size.pass.cpp
index 5c6a34867b39a..97219518ab4c5 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.capacity/size.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.capacity/size.pass.cpp
@@ -19,7 +19,7 @@
 #include "test_macros.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     typedef std::deque<int> C;
     C c;
@@ -72,6 +72,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/alloc.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/alloc.pass.cpp
index 4b19ef3e22173..55bbc0652737c 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/alloc.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/alloc.pass.cpp
@@ -20,23 +20,31 @@
 #include "min_allocator.h"
 
 template <class T, class Allocator>
-void test(const Allocator& a) {
+void test_util(const Allocator& a) {
   std::deque<T, Allocator> d(a);
   assert(d.size() == 0);
   assert(d.get_allocator() == a);
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(d));
 }
 
-int main(int, char**) {
-  test<int>(std::allocator<int>());
-  test<NotConstructible>(test_allocator<NotConstructible>(3));
+TEST_CONSTEXPR_CXX26 bool test() {
+  test_util<int>(std::allocator<int>());
+  test_util<NotConstructible>(test_allocator<NotConstructible>(3));
 #if TEST_STD_VER >= 11
-  test<int>(min_allocator<int>());
-  test<int>(safe_allocator<int>());
-  test<NotConstructible>(min_allocator<NotConstructible>{});
-  test<NotConstructible>(safe_allocator<NotConstructible>{});
-  test<int>(explicit_allocator<int>());
-  test<NotConstructible>(explicit_allocator<NotConstructible>{});
+  test_util<int>(min_allocator<int>());
+  test_util<int>(safe_allocator<int>());
+  test_util<NotConstructible>(min_allocator<NotConstructible>{});
+  test_util<NotConstructible>(safe_allocator<NotConstructible>{});
+  test_util<int>(explicit_allocator<int>());
+  test_util<NotConstructible>(explicit_allocator<NotConstructible>{});
+#endif
+  return false;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
 #endif
 
   return 0;
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/assign_initializer_list.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/assign_initializer_list.pass.cpp
index bc57098463eaa..6e2a5b1369e70 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/assign_initializer_list.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/assign_initializer_list.pass.cpp
@@ -19,7 +19,7 @@
 #include "test_macros.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     std::deque<int> d;
     d.assign({3, 4, 5, 6});
@@ -40,6 +40,13 @@ int main(int, char**) {
     assert(d[3] == 6);
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(d));
   }
+  return true;
+}
 
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/assign_iter_iter.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/assign_iter_iter.pass.cpp
index c57eb9d08cabe..5a1b29c02ca2e 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/assign_iter_iter.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/assign_iter_iter.pass.cpp
@@ -144,6 +144,8 @@ void test_iterators() {
 
 int main(int, char**) {
   basic_test();
-
+#if TEST_STD_VER >= 26
+  static_assert(basic_test());
+#endif
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/assign_size_value.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/assign_size_value.pass.cpp
index 30277125e46e1..97857088a77e4 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/assign_size_value.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/assign_size_value.pass.cpp
@@ -55,7 +55,7 @@ void testN(int start, int N, int M) {
   test(c1, M, -10);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -74,6 +74,14 @@ int main(int, char**) {
           testN<std::deque<int, min_allocator<int>> >(rng[i], rng[j], rng[k]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/copy.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/copy.pass.cpp
index 9f7a429d122a3..4de61a8445f1c 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/copy.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/copy.pass.cpp
@@ -26,7 +26,7 @@ void test(const C& x) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(x));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int ab[] = {3, 4, 2, 8, 0, 1, 44, 34, 45, 96, 80, 1, 13, 31, 45};
     int* an  = ab + sizeof(ab) / sizeof(ab[0]);
@@ -63,6 +63,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(v2));
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/copy_alloc.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/copy_alloc.pass.cpp
index fb3ad3c25a8f1..a93a28204abab 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/copy_alloc.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/copy_alloc.pass.cpp
@@ -26,7 +26,7 @@ void test(const C& x, const typename C::allocator_type& a) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int ab[] = {3, 4, 2, 8, 0, 1, 44, 34, 45, 96, 80, 1, 13, 31, 45};
     int* an  = ab + sizeof(ab) / sizeof(ab[0]);
@@ -49,6 +49,14 @@ int main(int, char**) {
     test(std::deque<int, safe_allocator<int> >(ab, an, safe_allocator<int>()), safe_allocator<int>());
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/deduct.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/deduct.pass.cpp
index c481ac59ab411..995eeb578f7b2 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/deduct.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/deduct.pass.cpp
@@ -32,7 +32,7 @@
 
 struct A {};
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   //  Test the explicit deduction guides
   {
     const int arr[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
@@ -156,6 +156,14 @@ int main(int, char**) {
 #endif
 
   SequenceContainerDeductionGuidesSfinaeAway<std::deque, std::deque<int>>();
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/deduct.verify.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/deduct.verify.cpp
index 61e58b08ca263..cbdcee4be91f5 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/deduct.verify.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/deduct.verify.cpp
@@ -22,7 +22,7 @@
 
 struct A {};
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   //  Test the explicit deduction guides
 
   //  Test the implicit deduction guides
@@ -34,6 +34,14 @@ int main(int, char**) {
     //  Also, we can't use {} instead of parens, because that constructs a
     //      deque<allocator<int>, allocator<allocator<int>>>
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/default.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/default.pass.cpp
index 6bfd4857f9b0a..f6fa7c642ff6c 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/default.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/default.pass.cpp
@@ -31,13 +31,21 @@ void test() {
 #endif
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   test<int, std::allocator<int> >();
   test<NotConstructible, limited_allocator<NotConstructible, 1> >();
 #if TEST_STD_VER >= 11
   test<int, min_allocator<int> >();
   test<NotConstructible, min_allocator<NotConstructible> >();
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/default_noexcept.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/default_noexcept.pass.cpp
index 244fef829f521..a37504dcb5568 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/default_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/default_noexcept.pass.cpp
@@ -29,7 +29,7 @@ struct some_alloc {
   void allocate(std::size_t);
 };
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
 #if defined(_LIBCPP_VERSION)
   {
     typedef std::deque<MoveOnly> C;
@@ -48,6 +48,14 @@ int main(int, char**) {
     typedef std::deque<MoveOnly, some_alloc<MoveOnly>> C;
     static_assert(!std::is_nothrow_default_constructible<C>::value, "");
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/dtor_noexcept.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/dtor_noexcept.pass.cpp
index f0a839484f9dc..8aa967ebe0885 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/dtor_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/dtor_noexcept.pass.cpp
@@ -27,7 +27,7 @@ struct some_alloc {
   void allocate(std::size_t);
 };
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     typedef std::deque<MoveOnly> C;
     static_assert(std::is_nothrow_destructible<C>::value, "");
@@ -46,6 +46,14 @@ int main(int, char**) {
     static_assert(!std::is_nothrow_destructible<C>::value, "");
   }
 #endif // _LIBCPP_VERSION
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/from_range.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/from_range.pass.cpp
index cfc07ab7bc797..251d6dc18d51d 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/from_range.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/from_range.pass.cpp
@@ -17,7 +17,7 @@
 // template<container-compatible-range<T> R>
 //   deque(from_range_t, R&& rg, const Allocator& = Allocator()); // C++23
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   for_all_iterators_and_allocators<int>([]<class Iter, class Sent, class Alloc>() {
     test_sequence_container<std::deque, int, Iter, Sent, Alloc>([]([[maybe_unused]] const auto& c) {
       LIBCPP_ASSERT(c.__invariants());
@@ -31,6 +31,14 @@ int main(int, char**) {
   // See https://github.com/llvm/llvm-project/issues/62056.
   //test_exception_safety_throwing_copy<std::deque>();
   //test_exception_safety_throwing_allocator<std::deque, int>();
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/initializer_list.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/initializer_list.pass.cpp
index d7df936f9413d..4c41ca54aafdd 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/initializer_list.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/initializer_list.pass.cpp
@@ -19,7 +19,7 @@
 #include "test_macros.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     std::deque<int> d = {3, 4, 5, 6};
     assert(d.size() == 4);
@@ -38,6 +38,14 @@ int main(int, char**) {
     assert(d[3] == 6);
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(d));
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/initializer_list_alloc.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/initializer_list_alloc.pass.cpp
index f5f1a23243002..3dd1d0c4dfc6a 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/initializer_list_alloc.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/initializer_list_alloc.pass.cpp
@@ -20,7 +20,7 @@
 #include "test_allocator.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     std::deque<int, test_allocator<int>> d({3, 4, 5, 6}, test_allocator<int>(3));
     assert(d.get_allocator() == test_allocator<int>(3));
@@ -41,6 +41,14 @@ int main(int, char**) {
     assert(d[3] == 6);
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(d));
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/iter_iter.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/iter_iter.pass.cpp
index 1f8a044d0b602..379c8a88b1d7d 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/iter_iter.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/iter_iter.pass.cpp
@@ -105,6 +105,9 @@ void test_emplacable_concept() {
 int main(int, char**) {
   basic_test();
   test_emplacable_concept();
-
+#if TEST_STD_VER >= 26
+  static_assert(basic_test());
+  static_assert(test_emplacable_concept());
+#endif
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/iter_iter_alloc.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/iter_iter_alloc.pass.cpp
index 61318c3d0f2d3..ec95a9ff7e6d1 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/iter_iter_alloc.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/iter_iter_alloc.pass.cpp
@@ -101,6 +101,10 @@ void test_emplacable_concept() {
 int main(int, char**) {
   basic_test();
   test_emplacable_concept();
+#if TEST_STD_VER >= 26
+  static_assert(basic_test());
+  static_assert(test_emplacable_concept());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/move.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/move.pass.cpp
index 66ff168cc83b7..ce4f6f5cd8eb6 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/move.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/move.pass.cpp
@@ -21,7 +21,7 @@
 #include "test_allocator.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     int ab[] = {3, 4, 2, 8, 0, 1, 44, 34, 45, 96, 80, 1, 13, 31, 45};
     int* an  = ab + sizeof(ab) / sizeof(ab[0]);
@@ -79,6 +79,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c2));
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c3));
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/move_alloc.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/move_alloc.pass.cpp
index 985d8ad9db67f..5940e05c56fd6 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/move_alloc.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/move_alloc.pass.cpp
@@ -21,7 +21,7 @@
 #include "test_allocator.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     int ab[]      = {3, 4, 2, 8, 0, 1, 44, 34, 45, 96, 80, 1, 13, 31, 45};
     const int* an = ab + sizeof(ab) / sizeof(ab[0]);
@@ -94,6 +94,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c2));
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c3));
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/move_assign.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/move_assign.pass.cpp
index 426dea0347101..06a6ae95e1b3c 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/move_assign.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/move_assign.pass.cpp
@@ -21,7 +21,7 @@
 #include "test_allocator.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     int ab[] = {3, 4, 2, 8, 0, 1, 44, 34, 45, 96, 80, 1, 13, 31, 45};
     int* an  = ab + sizeof(ab) / sizeof(ab[0]);
@@ -98,6 +98,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c2));
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c3));
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/move_noexcept.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/move_noexcept.pass.cpp
index 37e8a801e9d71..0b817ca34011c 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/move_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/move_noexcept.pass.cpp
@@ -29,7 +29,7 @@ struct some_alloc {
   void allocate(std::size_t);
 };
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
 #if defined(_LIBCPP_VERSION)
   {
     typedef std::deque<MoveOnly> C;
@@ -48,6 +48,14 @@ int main(int, char**) {
     static_assert(!std::is_nothrow_move_constructible<C>::value, "");
   }
 #endif // _LIBCPP_VERSION
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/op_equal.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/op_equal.pass.cpp
index 05d172268e0bd..1905db90c4156 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/op_equal.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/op_equal.pass.cpp
@@ -26,7 +26,7 @@ void test(const C& x) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(x));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     int ab[] = {3, 4, 2, 8, 0, 1, 44, 34, 45, 96, 80, 1, 13, 31, 45};
     int* an  = ab + sizeof(ab) / sizeof(ab[0]);
@@ -66,6 +66,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(l2));
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/op_equal_initializer_list.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/op_equal_initializer_list.pass.cpp
index b2760b4a3ff49..0a1743ff7c678 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/op_equal_initializer_list.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/op_equal_initializer_list.pass.cpp
@@ -19,7 +19,7 @@
 #include "test_macros.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     std::deque<int> d;
     d = {3, 4, 5, 6};
@@ -40,6 +40,14 @@ int main(int, char**) {
     assert(d[3] == 6);
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(d));
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/size.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/size.pass.cpp
index f8f42bd668f83..542288aefc3d0 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/size.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/size.pass.cpp
@@ -82,7 +82,7 @@ void test(unsigned n) {
   test2<T, Allocator>(n);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   test<DefaultOnly, std::allocator<DefaultOnly> >(0);
   test<DefaultOnly, std::allocator<DefaultOnly> >(1);
   test<DefaultOnly, std::allocator<DefaultOnly> >(10);
@@ -107,6 +107,14 @@ int main(int, char**) {
   test3<int, std::allocator<int>>(1);
   test3<int, min_allocator<int>>(3);
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/size_value.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/size_value.pass.cpp
index 231aa9c44c663..caeea946d0461 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/size_value.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/size_value.pass.cpp
@@ -31,7 +31,7 @@ void test(unsigned n, const T& x) {
     assert(*i == x);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   test<int, std::allocator<int> >(0, 5);
   test<int, std::allocator<int> >(1, 10);
   test<int, std::allocator<int> >(10, 11);
@@ -48,6 +48,14 @@ int main(int, char**) {
 #if TEST_STD_VER >= 11
   test<int, min_allocator<int> >(4095, 90);
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.cons/size_value_alloc.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.cons/size_value_alloc.pass.cpp
index f8ea37e64d9eb..4fd29052d59f1 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.cons/size_value_alloc.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.cons/size_value_alloc.pass.cpp
@@ -31,7 +31,7 @@ void test(unsigned n, const T& x, const Allocator& a) {
     assert(*i == x);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     std::allocator<int> a;
     test(0, 5, a);
@@ -64,6 +64,14 @@ int main(int, char**) {
     test(4097, 157, a);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.erasure/erase.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.erasure/erase.pass.cpp
index 947e06bd64375..583a229775d02 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.erasure/erase.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.erasure/erase.pass.cpp
@@ -66,7 +66,7 @@ void test() {
   test0(S({1, 2, 1}), opt(3), S({1, 2, 1}), 0);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   test<std::deque<int>>();
   test<std::deque<int, min_allocator<int>>>();
   test<std::deque<int, safe_allocator<int>>>();
@@ -74,6 +74,14 @@ int main(int, char**) {
 
   test<std::deque<long>>();
   test<std::deque<double>>();
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.erasure/erase_if.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.erasure/erase_if.pass.cpp
index ed5220422dab2..365bd1e88a881 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.erasure/erase_if.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.erasure/erase_if.pass.cpp
@@ -68,7 +68,7 @@ void test() {
   test0(S({1, 2, 3}), False, S({1, 2, 3}), 0);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   test<std::deque<int>>();
   test<std::deque<int, min_allocator<int>>>();
   test<std::deque<int, safe_allocator<int>>>();
@@ -76,6 +76,14 @@ int main(int, char**) {
 
   test<std::deque<long>>();
   test<std::deque<double>>();
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/append_range.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/append_range.pass.cpp
index 56a1d226db46f..c03212a12c011 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/append_range.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/append_range.pass.cpp
@@ -22,7 +22,8 @@
 //   {empty/one-element/full} container);
 // - appending move-only elements;
 // - an exception is thrown when copying the elements or when allocating new elements.
-int main(int, char**) {
+
+TEST_CONSTEXPR_CXX26 bool test() {
   static_assert(test_constraints_append_range<std::deque, int, double>());
 
   for_all_iterators_and_allocators<int, const int*>([]<class Iter, class Sent, class Alloc>() {
@@ -34,6 +35,14 @@ int main(int, char**) {
 
   test_append_range_exception_safety_throwing_copy<std::deque>();
   test_append_range_exception_safety_throwing_allocator<std::deque, int>();
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/assign_range.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/assign_range.pass.cpp
index 744e03a7b983e..556532a3919ae 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/assign_range.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/assign_range.pass.cpp
@@ -21,7 +21,8 @@
 //   {empty/one-element/full} container);
 // - assigning move-only elements;
 // - an exception is thrown when copying the elements or when allocating new elements.
-int main(int, char**) {
+
+TEST_CONSTEXPR_CXX26 bool test() {
   static_assert(test_constraints_assign_range<std::deque, int, double>());
 
   for_all_iterators_and_allocators<int, const int*>([]<class Iter, class Sent, class Alloc>() {
@@ -33,6 +34,14 @@ int main(int, char**) {
 
   test_assign_range_exception_safety_throwing_copy<std::deque>();
   test_assign_range_exception_safety_throwing_allocator<std::deque, int>();
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/clear.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/clear.pass.cpp
index bb2fa6e52af43..cb422c90c8e29 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/clear.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/clear.pass.cpp
@@ -18,7 +18,7 @@
 #include "../../../NotConstructible.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     typedef NotConstructible T;
     typedef std::deque<T> C;
@@ -69,6 +69,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace.pass.cpp
index 7c90216a9ce56..1667d6a80aa72 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace.pass.cpp
@@ -74,7 +74,7 @@ void testN(int start, int N) {
   }
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -96,6 +96,14 @@ int main(int, char**) {
       for (int j = 0; j < N; ++j)
         testN<std::deque<Emplaceable, safe_allocator<Emplaceable>> >(rng[i], rng[j]);
   }
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace_back.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace_back.pass.cpp
index 590ab432dd519..f10363846fbbc 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace_back.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace_back.pass.cpp
@@ -68,7 +68,7 @@ void testN(int start, int N) {
   test(c1);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -98,6 +98,14 @@ int main(int, char**) {
     assert(c.size() == 4);
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
   }
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace_front.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace_front.pass.cpp
index 3fbaee1fc1587..d77535e83a635 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace_front.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/emplace_front.pass.cpp
@@ -68,7 +68,7 @@ void testN(int start, int N) {
   test(c1);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -98,6 +98,14 @@ int main(int, char**) {
     assert(c.size() == 4);
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
   }
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter.invalidation.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter.invalidation.pass.cpp
index b538b0f037ab1..3de0d555f6642 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter.invalidation.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter.invalidation.pass.cpp
@@ -56,7 +56,7 @@ void del_at_end(C c) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   std::deque<int> queue;
   for (int i = 0; i < 20; ++i)
     queue.push_back(i);
@@ -66,6 +66,14 @@ int main(int, char**) {
     del_at_end(queue);
     queue.pop_back();
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter.pass.cpp
index 2d40f0c449f4d..3833a79443596 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter.pass.cpp
@@ -93,7 +93,7 @@ void testN(int start, int N) {
   }
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -126,6 +126,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(v));
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter_iter.invalidation.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter_iter.invalidation.pass.cpp
index 320d4771a2fc7..25b194bccf7fe 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter_iter.invalidation.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter_iter.invalidation.pass.cpp
@@ -60,7 +60,7 @@ void del_at_end(C c, std::size_t num) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   std::deque<int> queue;
   for (int i = 0; i < 20; ++i)
     queue.push_back(i);
@@ -72,6 +72,14 @@ int main(int, char**) {
     }
     queue.pop_back();
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter_iter.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter_iter.pass.cpp
index 1eaa7a6c72a57..3e757935b31af 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter_iter.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/erase_iter_iter.pass.cpp
@@ -99,7 +99,7 @@ void testN(int start, int N) {
   }
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -132,6 +132,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(v));
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_iter_initializer_list.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_iter_initializer_list.pass.cpp
index 117ce63b93d7e..5af86445069b9 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_iter_initializer_list.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_iter_initializer_list.pass.cpp
@@ -19,7 +19,7 @@
 #include "test_macros.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     std::deque<int> d(10, 1);
     std::deque<int>::iterator i = d.insert(d.cbegin() + 2, {3, 4, 5, 6});
@@ -62,6 +62,14 @@ int main(int, char**) {
     assert(d[13] == 1);
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(d));
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_iter_iter.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_iter_iter.pass.cpp
index 3941c1e8bc6c5..7da62fe7082de 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_iter_iter.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_iter_iter.pass.cpp
@@ -235,7 +235,7 @@ void test_move() {
 #endif
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -270,6 +270,14 @@ int main(int, char**) {
     test_move<std::deque<MoveOnly, safe_allocator<MoveOnly> > >();
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_range.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_range.pass.cpp
index 7681eb63b9076..b818ab5b7a91c 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_range.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_range.pass.cpp
@@ -26,7 +26,7 @@
 //   {empty/one-element/full} container at the {beginning/middle/end});
 // - inserting move-only elements;
 // - an exception is thrown when copying the elements or when allocating new elements.
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   static_assert(test_constraints_insert_range<std::deque, int, double>());
 
   for_all_iterators_and_allocators<int, const int*>([]<class Iter, class Sent, class Alloc>() {
@@ -38,6 +38,14 @@ int main(int, char**) {
 
   test_insert_range_exception_safety_throwing_copy<std::deque>();
   test_insert_range_exception_safety_throwing_allocator<std::deque, int>();
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_rvalue.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_rvalue.pass.cpp
index ff4654cf0ccb3..8ab016ef2a6c1 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_rvalue.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_rvalue.pass.cpp
@@ -80,7 +80,7 @@ void testN(int start, int N) {
   }
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -102,6 +102,14 @@ int main(int, char**) {
       for (int j = 0; j < N; ++j)
         testN<std::deque<MoveOnly, safe_allocator<MoveOnly>> >(rng[i], rng[j]);
   }
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_size_value.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_size_value.pass.cpp
index 05a16a9e76387..62df9952e1b4e 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_size_value.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_size_value.pass.cpp
@@ -113,7 +113,7 @@ void self_reference_test() {
   }
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -143,6 +143,14 @@ int main(int, char**) {
     self_reference_test<std::deque<int, safe_allocator<int>> >();
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_value.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_value.pass.cpp
index b9440acb4986a..e13944e458862 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_value.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/insert_value.pass.cpp
@@ -99,7 +99,7 @@ void self_reference_test() {
   }
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -126,6 +126,14 @@ int main(int, char**) {
     self_reference_test<std::deque<int, safe_allocator<int>> >();
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_back.invalidation.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_back.invalidation.pass.cpp
index 3d0133e362b6a..baa9202524d70 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_back.invalidation.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_back.invalidation.pass.cpp
@@ -37,7 +37,7 @@ void test(C c) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   std::deque<int> queue;
   for (int i = 0; i < 4098; ++i)
     queue.push_back(i);
@@ -47,6 +47,14 @@ int main(int, char**) {
     queue.pop_back();
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(queue));
   }
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_back.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_back.pass.cpp
index 301d8e3342bb6..bb51057837cb4 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_back.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_back.pass.cpp
@@ -58,7 +58,7 @@ void testN(int start, int N) {
   }
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -82,6 +82,14 @@ int main(int, char**) {
         testN<std::deque<int, safe_allocator<int>> >(rng[i], rng[j]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_front.invalidation.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_front.invalidation.pass.cpp
index c857c3038d49e..35518330040cb 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_front.invalidation.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_front.invalidation.pass.cpp
@@ -36,7 +36,7 @@ void test(C c) {
   assert(&*it2 == &*it4);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   std::deque<int> queue;
   for (int i = 0; i < 4098; ++i)
     queue.push_back(i);
@@ -46,6 +46,14 @@ int main(int, char**) {
     queue.pop_back();
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(queue));
   }
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_front.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_front.pass.cpp
index 2bd390ac315e0..54226d4c7f331 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_front.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/pop_front.pass.cpp
@@ -58,7 +58,7 @@ void testN(int start, int N) {
   }
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -75,6 +75,14 @@ int main(int, char**) {
         testN<std::deque<int, min_allocator<int>> >(rng[i], rng[j]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/prepend_range.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/prepend_range.pass.cpp
index 3154cd389d2f0..ae62d60ebe6b4 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/prepend_range.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/prepend_range.pass.cpp
@@ -22,7 +22,7 @@
 //   {empty/one-element/full} container);
 // - prepending move-only elements;
 // - an exception is thrown when copying the elements or when allocating new elements.
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   static_assert(test_constraints_prepend_range<std::deque, int, double>());
 
   for_all_iterators_and_allocators<int, const int*>([]<class Iter, class Sent, class Alloc>() {
@@ -34,6 +34,14 @@ int main(int, char**) {
 
   test_prepend_range_exception_safety_throwing_copy<std::deque>();
   test_prepend_range_exception_safety_throwing_allocator<std::deque, int>();
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back.pass.cpp
index fff3433ab4dd4..b63f802ee02ad 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back.pass.cpp
@@ -51,7 +51,7 @@ void test(int size) {
   }
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2046, 2047, 2048, 2049, 4094, 4095, 4096};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -66,6 +66,14 @@ int main(int, char**) {
       test<std::deque<int, min_allocator<int>> >(rng[j]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back_exception_safety.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back_exception_safety.pass.cpp
index 10da5b02f96f1..68e4be4387fb4 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back_exception_safety.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back_exception_safety.pass.cpp
@@ -68,7 +68,7 @@ CMyClass::~CMyClass() {
 
 bool operator==(const CMyClass& lhs, const CMyClass& rhs) { return lhs.equal(rhs); }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   CMyClass instance(42);
   {
     std::deque<CMyClass> vec;
@@ -100,6 +100,14 @@ int main(int, char**) {
       assert(vec == vec2);
     }
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back_rvalue.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back_rvalue.pass.cpp
index c9e0ca7a6d7e0..1e12650d6234b 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back_rvalue.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_back_rvalue.pass.cpp
@@ -54,7 +54,7 @@ void test(int size) {
   }
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2046, 2047, 2048, 2049, 4094, 4095, 4096};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -73,6 +73,14 @@ int main(int, char**) {
     for (int j = 0; j < N; ++j)
       test<std::deque<MoveOnly, safe_allocator<MoveOnly>> >(rng[j]);
   }
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front.pass.cpp
index 1fb8341895a35..50ac046e14453 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front.pass.cpp
@@ -58,7 +58,7 @@ void testN(int start, int N) {
   test(c1, -10);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -82,6 +82,14 @@ int main(int, char**) {
         testN<std::deque<int, safe_allocator<int>> >(rng[i], rng[j]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front_exception_safety.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front_exception_safety.pass.cpp
index f4b77bcf09f62..76ad9367cce25 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front_exception_safety.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front_exception_safety.pass.cpp
@@ -68,7 +68,7 @@ CMyClass::~CMyClass() {
 
 bool operator==(const CMyClass& lhs, const CMyClass& rhs) { return lhs.equal(rhs); }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   CMyClass instance(42);
   {
     std::deque<CMyClass> vec;
@@ -100,6 +100,14 @@ int main(int, char**) {
       assert(vec == vec2);
     }
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front_rvalue.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front_rvalue.pass.cpp
index 418a0c976e66c..24e2bcb5f1c3a 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front_rvalue.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.modifiers/push_front_rvalue.pass.cpp
@@ -61,7 +61,7 @@ void testN(int start, int N) {
   test(c1, -10);
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -76,6 +76,14 @@ int main(int, char**) {
       for (int j = 0; j < N; ++j)
         testN<std::deque<MoveOnly, safe_allocator<MoveOnly>> >(rng[i], rng[j]);
   }
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.special/copy.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.special/copy.pass.cpp
index 382d6e530b24f..dc926670de6f7 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.special/copy.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.special/copy.pass.cpp
@@ -76,7 +76,7 @@ void testN(int start, int N) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c2));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -93,6 +93,14 @@ int main(int, char**) {
         testN<std::deque<int, min_allocator<int>> >(rng[i], rng[j]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.special/copy_backward.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.special/copy_backward.pass.cpp
index 1414f03a549c1..cc6f6a77e8ed6 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.special/copy_backward.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.special/copy_backward.pass.cpp
@@ -75,7 +75,7 @@ void testN(int start, int N) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c2));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -92,6 +92,14 @@ int main(int, char**) {
         testN<std::deque<int, min_allocator<int>> >(rng[i], rng[j]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.special/move.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.special/move.pass.cpp
index 4b24141db3cee..de4c65c7eba0e 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.special/move.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.special/move.pass.cpp
@@ -75,7 +75,7 @@ void testN(int start, int N) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c2));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -92,6 +92,14 @@ int main(int, char**) {
         testN<std::deque<int, min_allocator<int>> >(rng[i], rng[j]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.special/move_backward.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.special/move_backward.pass.cpp
index 726abe7617aef..523a479eef005 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.special/move_backward.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.special/move_backward.pass.cpp
@@ -75,7 +75,7 @@ void testN(int start, int N) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c2));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -92,6 +92,14 @@ int main(int, char**) {
         testN<std::deque<int, min_allocator<int> > >(rng[i], rng[j]);
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.special/swap.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.special/swap.pass.cpp
index 07004315a0bfb..13a1b8735e0d8 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.special/swap.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.special/swap.pass.cpp
@@ -52,7 +52,7 @@ void testN(int start, int N, int M) {
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c2_save));
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   {
     int rng[]   = {0, 1, 2, 3, 1023, 1024, 1025, 2047, 2048, 2049};
     const int N = sizeof(rng) / sizeof(rng[0]);
@@ -113,6 +113,14 @@ int main(int, char**) {
     LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(c2));
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/deque.special/swap_noexcept.pass.cpp b/libcxx/test/std/containers/sequences/deque/deque.special/swap_noexcept.pass.cpp
index 6347496d67c15..97c61322f4e73 100644
--- a/libcxx/test/std/containers/sequences/deque/deque.special/swap_noexcept.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/deque.special/swap_noexcept.pass.cpp
@@ -52,7 +52,7 @@ struct some_alloc2 {
   typedef std::true_type is_always_equal;
 };
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     typedef std::deque<MoveOnly> C;
     static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
@@ -83,6 +83,14 @@ int main(int, char**) {
     static_assert(noexcept(swap(std::declval<C&>(), std::declval<C&>())), "");
   }
 #endif
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/get_allocator.pass.cpp b/libcxx/test/std/containers/sequences/deque/get_allocator.pass.cpp
index 6b8bc6c555bcd..38cb73cfe5e28 100644
--- a/libcxx/test/std/containers/sequences/deque/get_allocator.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/get_allocator.pass.cpp
@@ -18,7 +18,7 @@
 #include "test_allocator.h"
 #include "test_macros.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     std::allocator<int> alloc;
     const std::deque<int> d(alloc);
@@ -29,6 +29,14 @@ int main(int, char**) {
     const std::deque<int, other_allocator<int> > d(alloc);
     assert(d.get_allocator() == alloc);
   }
+  return true;
+}
+
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/iterators.pass.cpp b/libcxx/test/std/containers/sequences/deque/iterators.pass.cpp
index 337fd688ebcdb..604a5a79d9671 100644
--- a/libcxx/test/std/containers/sequences/deque/iterators.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/iterators.pass.cpp
@@ -22,7 +22,7 @@
 #include "test_macros.h"
 #include "min_allocator.h"
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool test() {
   {
     typedef std::deque<int> C;
     C c;
@@ -104,6 +104,13 @@ int main(int, char**) {
 #  endif // TEST_STD_VER > 20
   }
 #endif
+  return true;
+}
 
+int main(int, char**) {
+  test();
+#if TEST_STD_VER >= 26
+  static_assert(test());
+#endif
   return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/deque/types.pass.cpp b/libcxx/test/std/containers/sequences/deque/types.pass.cpp
index 8184d55873d20..da12694aa14c0 100644
--- a/libcxx/test/std/containers/sequences/deque/types.pass.cpp
+++ b/libcxx/test/std/containers/sequences/deque/types.pass.cpp
@@ -77,7 +77,7 @@ void test() {
                 "");
 }
 
-int main(int, char**) {
+TEST_CONSTEXPR_CXX26 bool tests() {
   test<int, test_allocator<int> >();
   test<int*, std::allocator<int*> >();
   test<Copyable, test_allocator<Copyable> >();
@@ -106,6 +106,14 @@ int main(int, char**) {
                   "");
   }
 #endif
+  return false;
+}
+
+int main(int, char**) {
+  tests();
+#if TEST_STD_VER >= 26
+  static_assert(tests());
+#endif
 
   return 0;
 }
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/deque.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/deque.version.compile.pass.cpp
index d0e4ac130c60e..1cc6fbcf49944 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/deque.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/deque.version.compile.pass.cpp
@@ -17,6 +17,7 @@
 
 /*  Constant                                                Value
     __cpp_lib_allocator_traits_is_always_equal              201411L [C++17]
+    __cpp_lib_constexpr_deque                               202502L [C++26]
     __cpp_lib_containers_ranges                             202202L [C++23]
     __cpp_lib_default_template_type_for_algorithm_values    202403L [C++26]
     __cpp_lib_erase_if                                      202002L [C++20]
@@ -32,6 +33,10 @@
 #   error "__cpp_lib_allocator_traits_is_always_equal should not be defined before c++17"
 # endif
 
+# ifdef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should not be defined before c++26"
+# endif
+
 # ifdef __cpp_lib_containers_ranges
 #   error "__cpp_lib_containers_ranges should not be defined before c++23"
 # endif
@@ -54,6 +59,10 @@
 #   error "__cpp_lib_allocator_traits_is_always_equal should not be defined before c++17"
 # endif
 
+# ifdef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should not be defined before c++26"
+# endif
+
 # ifdef __cpp_lib_containers_ranges
 #   error "__cpp_lib_containers_ranges should not be defined before c++23"
 # endif
@@ -79,6 +88,10 @@
 #   error "__cpp_lib_allocator_traits_is_always_equal should have the value 201411L in c++17"
 # endif
 
+# ifdef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should not be defined before c++26"
+# endif
+
 # ifdef __cpp_lib_containers_ranges
 #   error "__cpp_lib_containers_ranges should not be defined before c++23"
 # endif
@@ -107,6 +120,10 @@
 #   error "__cpp_lib_allocator_traits_is_always_equal should have the value 201411L in c++20"
 # endif
 
+# ifdef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should not be defined before c++26"
+# endif
+
 # ifdef __cpp_lib_containers_ranges
 #   error "__cpp_lib_containers_ranges should not be defined before c++23"
 # endif
@@ -138,6 +155,10 @@
 #   error "__cpp_lib_allocator_traits_is_always_equal should have the value 201411L in c++23"
 # endif
 
+# ifdef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should not be defined before c++26"
+# endif
+
 # ifndef __cpp_lib_containers_ranges
 #   error "__cpp_lib_containers_ranges should be defined in c++23"
 # endif
@@ -172,6 +193,13 @@
 #   error "__cpp_lib_allocator_traits_is_always_equal should have the value 201411L in c++26"
 # endif
 
+# ifndef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should be defined in c++26"
+# endif
+# if __cpp_lib_constexpr_deque != 202502L
+#   error "__cpp_lib_constexpr_deque should have the value 202502L in c++26"
+# endif
+
 # ifndef __cpp_lib_containers_ranges
 #   error "__cpp_lib_containers_ranges should be defined in c++26"
 # endif
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
index 9b318f2deabc4..6e262e83a1423 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
@@ -61,6 +61,7 @@
     __cpp_lib_constexpr_charconv                            202207L [C++23]
     __cpp_lib_constexpr_cmath                               202202L [C++23]
     __cpp_lib_constexpr_complex                             201711L [C++20]
+    __cpp_lib_constexpr_deque                               202502L [C++26]
     __cpp_lib_constexpr_dynamic_alloc                       201907L [C++20]
     __cpp_lib_constexpr_functional                          201907L [C++20]
     __cpp_lib_constexpr_iterator                            201811L [C++20]
@@ -427,6 +428,10 @@
 #   error "__cpp_lib_constexpr_complex should not be defined before c++20"
 # endif
 
+# ifdef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should not be defined before c++26"
+# endif
+
 # ifdef __cpp_lib_constexpr_dynamic_alloc
 #   error "__cpp_lib_constexpr_dynamic_alloc should not be defined before c++20"
 # endif
@@ -1303,6 +1308,10 @@
 #   error "__cpp_lib_constexpr_complex should not be defined before c++20"
 # endif
 
+# ifdef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should not be defined before c++26"
+# endif
+
 # ifdef __cpp_lib_constexpr_dynamic_alloc
 #   error "__cpp_lib_constexpr_dynamic_alloc should not be defined before c++20"
 # endif
@@ -2281,6 +2290,10 @@
 #   error "__cpp_lib_constexpr_complex should not be defined before c++20"
 # endif
 
+# ifdef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should not be defined before c++26"
+# endif
+
 # ifdef __cpp_lib_constexpr_dynamic_alloc
 #   error "__cpp_lib_constexpr_dynamic_alloc should not be defined before c++20"
 # endif
@@ -3496,6 +3509,10 @@
 #   error "__cpp_lib_constexpr_complex should have the value 201711L in c++20"
 # endif
 
+# ifdef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should not be defined before c++26"
+# endif
+
 # ifndef __cpp_lib_constexpr_dynamic_alloc
 #   error "__cpp_lib_constexpr_dynamic_alloc should be defined in c++20"
 # endif
@@ -4936,6 +4953,10 @@
 #   error "__cpp_lib_constexpr_complex should have the value 201711L in c++23"
 # endif
 
+# ifdef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should not be defined before c++26"
+# endif
+
 # ifndef __cpp_lib_constexpr_dynamic_alloc
 #   error "__cpp_lib_constexpr_dynamic_alloc should be defined in c++23"
 # endif
@@ -6592,6 +6613,13 @@
 #   error "__cpp_lib_constexpr_complex should have the value 201711L in c++26"
 # endif
 
+# ifndef __cpp_lib_constexpr_deque
+#   error "__cpp_lib_constexpr_deque should be defined in c++26"
+# endif
+# if __cpp_lib_constexpr_deque != 202502L
+#   error "__cpp_lib_constexpr_deque should have the value 202502L in c++26"
+# endif
+
 # ifndef __cpp_lib_constexpr_dynamic_alloc
 #   error "__cpp_lib_constexpr_dynamic_alloc should be defined in c++26"
 # endif
diff --git a/libcxx/utils/generate_feature_test_macro_components.py b/libcxx/utils/generate_feature_test_macro_components.py
index 6a9c7b4ea586c..e9e62369474d1 100755
--- a/libcxx/utils/generate_feature_test_macro_components.py
+++ b/libcxx/utils/generate_feature_test_macro_components.py
@@ -345,6 +345,11 @@ def add_version_header(tc):
             "values": {"c++20": 201711},
             "headers": ["complex"],
         },
+        {
+            "name": "__cpp_lib_constexpr_deque",
+            "values": {"c++26": 202502},
+            "headers": ["deque"],
+        },
         {
             "name": "__cpp_lib_constexpr_dynamic_alloc",
             "values": {"c++20": 201907},