diff --git a/libcxx/include/__vector/vector_bool.h b/libcxx/include/__vector/vector_bool.h
index 36eb7f350ac40..a5f0eb0751e0f 100644
--- a/libcxx/include/__vector/vector_bool.h
+++ b/libcxx/include/__vector/vector_bool.h
@@ -699,14 +699,7 @@ template <class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 vector<bool, _Allocator>& vector<bool, _Allocator>::operator=(const vector& __v) {
   if (this != std::addressof(__v)) {
     __copy_assign_alloc(__v);
-    if (__v.__size_) {
-      if (__v.__size_ > capacity()) {
-        __vdeallocate();
-        __vallocate(__v.__size_);
-      }
-      std::copy(__v.__begin_, __v.__begin_ + __external_cap_to_internal(__v.__size_), __begin_);
-    }
-    __size_ = __v.__size_;
+    __assign_with_size(__v.begin(), __v.end(), __v.size());
   }
   return *this;
 }
@@ -754,7 +747,7 @@ vector<bool, _Allocator>::operator=(vector&& __v)
 template <class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::__move_assign(vector& __c, false_type) {
   if (__alloc_ != __c.__alloc_)
-    assign(__c.begin(), __c.end());
+    __assign_with_size(__c.begin(), __c.end(), __c.size());
   else
     __move_assign(__c, true_type());
 }
@@ -773,19 +766,14 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::__move_assign(vecto
 
 template <class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 void vector<bool, _Allocator>::assign(size_type __n, const value_type& __x) {
-  __size_ = 0;
   if (__n > 0) {
-    size_type __c = capacity();
-    if (__n <= __c)
-      __size_ = __n;
-    else {
-      vector __v(get_allocator());
-      __v.reserve(__recommend(__n));
-      __v.__size_ = __n;
-      swap(__v);
+    if (__n > capacity()) {
+      __vdeallocate();
+      __vallocate(__n);
     }
     std::fill_n(begin(), __n, __x);
   }
+  this->__size_ = __n;
 }
 
 template <class _Allocator>
@@ -814,17 +802,15 @@ template <class _ForwardIterator, class _Sentinel>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void
 vector<bool, _Allocator>::__assign_with_size(_ForwardIterator __first, _Sentinel __last, difference_type __ns) {
   _LIBCPP_ASSERT_VALID_INPUT_RANGE(__ns >= 0, "invalid range specified");
-
-  clear();
-
-  const size_t __n = static_cast<size_type>(__ns);
+  const size_type __n = static_cast<size_type>(__ns);
   if (__n) {
     if (__n > capacity()) {
       __vdeallocate();
       __vallocate(__n);
     }
-    __construct_at_end(__first, __last, __n);
+    std::__copy(__first, __last, this->begin());
   }
+  this->__size_ = __n;
 }
 
 template <class _Allocator>
diff --git a/libcxx/test/std/containers/sequences/vector.bool/assign_copy.pass.cpp b/libcxx/test/std/containers/sequences/vector.bool/assign_copy.pass.cpp
index c4866ea4c9b45..889acb88bfcec 100644
--- a/libcxx/test/std/containers/sequences/vector.bool/assign_copy.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector.bool/assign_copy.pass.cpp
@@ -10,46 +10,65 @@
 
 // vector& operator=(const vector& c);
 
-#include <vector>
 #include <cassert>
-#include "test_macros.h"
-#include "test_allocator.h"
+#include <vector>
+
 #include "min_allocator.h"
+#include "test_allocator.h"
+#include "test_macros.h"
 
-TEST_CONSTEXPR_CXX20 bool tests()
-{
-    {
-        std::vector<bool, test_allocator<bool> > l(3, true, test_allocator<bool>(5));
-        std::vector<bool, test_allocator<bool> > l2(l, test_allocator<bool>(3));
-        l2 = l;
-        assert(l2 == l);
-        assert(l2.get_allocator() == test_allocator<bool>(3));
-    }
-    {
-        std::vector<bool, other_allocator<bool> > l(3, true, other_allocator<bool>(5));
-        std::vector<bool, other_allocator<bool> > l2(l, other_allocator<bool>(3));
-        l2 = l;
-        assert(l2 == l);
-        assert(l2.get_allocator() == other_allocator<bool>(5));
-    }
+TEST_CONSTEXPR_CXX20 bool tests() {
+  // Test with insufficient space where reallocation occurs during assignment
+  {
+    std::vector<bool, test_allocator<bool> > l(3, true, test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > l2(l, test_allocator<bool>(3));
+    l2 = l;
+    assert(l2 == l);
+    assert(l2.get_allocator() == test_allocator<bool>(3));
+  }
+  {
+    std::vector<bool, other_allocator<bool> > l(3, true, other_allocator<bool>(5));
+    std::vector<bool, other_allocator<bool> > l2(l, other_allocator<bool>(3));
+    l2 = l;
+    assert(l2 == l);
+    assert(l2.get_allocator() == other_allocator<bool>(5));
+  }
 #if TEST_STD_VER >= 11
-    {
-        std::vector<bool, min_allocator<bool> > l(3, true, min_allocator<bool>());
-        std::vector<bool, min_allocator<bool> > l2(l, min_allocator<bool>());
-        l2 = l;
-        assert(l2 == l);
-        assert(l2.get_allocator() == min_allocator<bool>());
-    }
+  {
+    std::vector<bool, min_allocator<bool> > l(3, true, min_allocator<bool>());
+    std::vector<bool, min_allocator<bool> > l2(l, min_allocator<bool>());
+    l2 = l;
+    assert(l2 == l);
+    assert(l2.get_allocator() == min_allocator<bool>());
+  }
 #endif
 
-    return true;
+  // Test with sufficient size where no reallocation occurs during assignment
+  {
+    std::vector<bool, test_allocator<bool> > l(4, true, test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > l2(5, false, test_allocator<bool>(3));
+    l2 = l;
+    assert(l2 == l);
+    assert(l2.get_allocator() == test_allocator<bool>(3));
+  }
+
+  // Test with sufficient spare space where no reallocation occurs during assignment
+  {
+    std::vector<bool, test_allocator<bool> > l(4, true, test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > l2(2, false, test_allocator<bool>(3));
+    l2.reserve(5);
+    l2 = l;
+    assert(l2 == l);
+    assert(l2.get_allocator() == test_allocator<bool>(3));
+  }
+
+  return true;
 }
 
-int main(int, char**)
-{
-    tests();
+int main(int, char**) {
+  tests();
 #if TEST_STD_VER > 17
-    static_assert(tests());
+  static_assert(tests());
 #endif
-    return 0;
+  return 0;
 }
diff --git a/libcxx/test/std/containers/sequences/vector.bool/assign_move.pass.cpp b/libcxx/test/std/containers/sequences/vector.bool/assign_move.pass.cpp
index 10271efc3f403..e047807d68f73 100644
--- a/libcxx/test/std/containers/sequences/vector.bool/assign_move.pass.cpp
+++ b/libcxx/test/std/containers/sequences/vector.bool/assign_move.pass.cpp
@@ -12,79 +12,116 @@
 
 // vector& operator=(vector&& c);
 
-#include <vector>
 #include <cassert>
-#include "test_macros.h"
-#include "test_allocator.h"
+#include <vector>
+
 #include "min_allocator.h"
+#include "test_allocator.h"
+#include "test_macros.h"
 
-TEST_CONSTEXPR_CXX20 bool tests()
-{
-    {
-        std::vector<bool, test_allocator<bool> > l(test_allocator<bool>(5));
-        std::vector<bool, test_allocator<bool> > lo(test_allocator<bool>(5));
-        for (int i = 1; i <= 3; ++i)
-        {
-            l.push_back(i);
-            lo.push_back(i);
-        }
-        std::vector<bool, test_allocator<bool> > l2(test_allocator<bool>(5));
-        l2 = std::move(l);
-        assert(l2 == lo);
-        LIBCPP_ASSERT(l.empty());
-        assert(l2.get_allocator() == lo.get_allocator());
+TEST_CONSTEXPR_CXX20 bool tests() {
+  //
+  // Testing for O(1) ownership move
+  //
+  { // Test with pocma = true_type, thus performing an ownership move.
+    std::vector<bool, other_allocator<bool> > l(other_allocator<bool>(5));
+    std::vector<bool, other_allocator<bool> > lo(other_allocator<bool>(5));
+    std::vector<bool, other_allocator<bool> > l2(other_allocator<bool>(6));
+    for (int i = 1; i <= 3; ++i) {
+      l.push_back(i);
+      lo.push_back(i);
+    }
+    l2 = std::move(l);
+    assert(l2 == lo);
+    assert(l.empty());
+    assert(l2.get_allocator() == lo.get_allocator());
+  }
+  { // Test with pocma = false_type and equal allocators, thus performing an ownership move.
+    std::vector<bool, test_allocator<bool> > l(test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > lo(test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > l2(test_allocator<bool>(5));
+    for (int i = 1; i <= 3; ++i) {
+      l.push_back(i);
+      lo.push_back(i);
     }
-    {
-        std::vector<bool, test_allocator<bool> > l(test_allocator<bool>(5));
-        std::vector<bool, test_allocator<bool> > lo(test_allocator<bool>(5));
-        for (int i = 1; i <= 3; ++i)
-        {
-            l.push_back(i);
-            lo.push_back(i);
-        }
-        std::vector<bool, test_allocator<bool> > l2(test_allocator<bool>(6));
-        l2 = std::move(l);
-        assert(l2 == lo);
-        assert(!l.empty());
-        assert(l2.get_allocator() == test_allocator<bool>(6));
+    l2 = std::move(l);
+    assert(l2 == lo);
+    LIBCPP_ASSERT(l.empty());
+    assert(l2.get_allocator() == lo.get_allocator());
+  }
+  { // Test with pocma = false_type and equal allocators, thus performing an ownership move.
+    std::vector<bool, min_allocator<bool> > l(min_allocator<bool>{});
+    std::vector<bool, min_allocator<bool> > lo(min_allocator<bool>{});
+    std::vector<bool, min_allocator<bool> > l2(min_allocator<bool>{});
+    for (int i = 1; i <= 3; ++i) {
+      l.push_back(i);
+      lo.push_back(i);
     }
-    {
-        std::vector<bool, other_allocator<bool> > l(other_allocator<bool>(5));
-        std::vector<bool, other_allocator<bool> > lo(other_allocator<bool>(5));
-        for (int i = 1; i <= 3; ++i)
-        {
-            l.push_back(i);
-            lo.push_back(i);
-        }
-        std::vector<bool, other_allocator<bool> > l2(other_allocator<bool>(6));
-        l2 = std::move(l);
-        assert(l2 == lo);
-        assert(l.empty());
-        assert(l2.get_allocator() == lo.get_allocator());
+    l2 = std::move(l);
+    assert(l2 == lo);
+    assert(l.empty());
+    assert(l2.get_allocator() == lo.get_allocator());
+  }
+
+  //
+  // Testing for O(n) element-wise move
+  //
+  { // Test with pocma = false_type and unequal allocators, thus performing an element-wise move.
+    // Reallocation occurs during the element-wise move due to insufficient space.
+    std::vector<bool, test_allocator<bool> > l(test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > lo(test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > l2(test_allocator<bool>(6));
+    for (int i = 1; i <= 3; ++i) {
+      l.push_back(i);
+      lo.push_back(i);
+    }
+    l2 = std::move(l);
+    assert(l2 == lo);
+    assert(!l.empty());
+    assert(l2.get_allocator() == test_allocator<bool>(6));
+  }
+
+  { // Test with pocma = false_type and unequal allocators, thus performing an element-wise move.
+    // No reallocation occurs since source data fits within current size.
+    std::vector<bool, test_allocator<bool> > l(test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > lo(test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > l2(test_allocator<bool>(6));
+    for (int i = 1; i <= 3; ++i) {
+      l.push_back(i);
+      lo.push_back(i);
     }
-    {
-        std::vector<bool, min_allocator<bool> > l(min_allocator<bool>{});
-        std::vector<bool, min_allocator<bool> > lo(min_allocator<bool>{});
-        for (int i = 1; i <= 3; ++i)
-        {
-            l.push_back(i);
-            lo.push_back(i);
-        }
-        std::vector<bool, min_allocator<bool> > l2(min_allocator<bool>{});
-        l2 = std::move(l);
-        assert(l2 == lo);
-        assert(l.empty());
-        assert(l2.get_allocator() == lo.get_allocator());
+    for (int i = 1; i <= 5; ++i)
+      l2.push_back(i);
+    l2 = std::move(l);
+    assert(l2 == lo);
+    assert(!l.empty());
+    assert(l2.get_allocator() == test_allocator<bool>(6));
+  }
+  { // Test with pocma = false_type and unequal allocators, thus performing an element-wise move.
+    // No reallocation occurs since source data fits within current spare space.
+    std::vector<bool, test_allocator<bool> > l(test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > lo(test_allocator<bool>(5));
+    std::vector<bool, test_allocator<bool> > l2(test_allocator<bool>(6));
+    for (int i = 1; i <= 3; ++i) {
+      l.push_back(i);
+      lo.push_back(i);
     }
+    for (int i = 1; i <= 2; ++i)
+      l2.push_back(i);
+    l2.reserve(5);
+    l2 = std::move(l);
+    assert(l2 == lo);
+    assert(!l.empty());
+    assert(l2.get_allocator() == test_allocator<bool>(6));
+  }
 
-    return true;
+  return true;
 }
 
-int main(int, char**)
-{
-    tests();
+int main(int, char**) {
+  tests();
 #if TEST_STD_VER > 17
-    static_assert(tests());
+  static_assert(tests());
 #endif
-    return 0;
+  return 0;
 }