[libc++] Avoid overloaded operator, for (T, Iter) cases

Several components in libc++ aren't defending against overloaded
`operator,(T, Iter)` currently. Existing deleted overloads in
`test_iterators.h` are insufficient for such cases.

This PR adds corresponding deleted overloads with reversed order and
fixes these libc++ components.
- `piecewise_linear_distribution`'s iterator pair constructor,
- `piecewise_linear_distribution::param_type`'s iterator pair
constructor,
- `piecewise_constant_distribution`'s iterator pair constructor,
- `piecewise_constant_distribution::param_type`'s iterator pair
constructor,
- `money_get::do_get`,
- `money_put::do_put`, and
- `num_put::do_put`.

Author: frederick-vs-ja

libcxx/include/__locale_dir/money.h

@@ -433,7 +433,7 @@ bool money_get<_CharT, _InputIterator>::__do_get(
           __err |= ios_base::failbit;
           return false;
         }
-        for (++__b; __fd > 0; --__fd, ++__b) {
+        for (++__b; __fd > 0; --__fd, (void)++__b) {
           if (__b == __e || !__ct.is(ctype_base::digit, *__b)) {
             __err |= ios_base::failbit;
             return false;
@@ -451,7 +451,7 @@ bool money_get<_CharT, _InputIterator>::__do_get(
     }
   }
   if (__trailing_sign) {
-    for (unsigned __i = 1; __i < __trailing_sign->size(); ++__i, ++__b) {
+    for (unsigned __i = 1; __i < __trailing_sign->size(); ++__i, (void)++__b) {
       if (__b == __e || *__b != (*__trailing_sign)[__i]) {
         __err |= ios_base::failbit;
         return false;

libcxx/include/__locale_dir/num.h

@@ -885,7 +885,7 @@ num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob, char_ty
   const numpunct<char_type>& __np = std::use_facet<numpunct<char_type> >(__iob.getloc());
   typedef typename numpunct<char_type>::string_type string_type;
   string_type __nm = __v ? __np.truename() : __np.falsename();
-  for (typename string_type::iterator __i = __nm.begin(); __i != __nm.end(); ++__i, ++__s)
+  for (typename string_type::iterator __i = __nm.begin(); __i != __nm.end(); ++__i, (void)++__s)
     *__s = *__i;
   return __s;
 }

libcxx/include/__locale_dir/pad_and_output.h

@@ -30,11 +30,11 @@ _LIBCPP_HIDE_FROM_ABI _OutputIterator __pad_and_output(
     __ns -= __sz;
   else
     __ns = 0;
-  for (; __ob < __op; ++__ob, ++__s)
+  for (; __ob < __op; ++__ob, (void)++__s)
     *__s = *__ob;
-  for (; __ns; --__ns, ++__s)
+  for (; __ns; --__ns, (void)++__s)
     *__s = __fl;
-  for (; __ob < __oe; ++__ob, ++__s)
+  for (; __ob < __oe; ++__ob, (void)++__s)
     *__s = *__ob;
   __iob.width(0);
   return __s;

libcxx/include/__random/piecewise_constant_distribution.h

@@ -190,7 +190,7 @@ piecewise_constant_distribution<_RealType>::param_type::param_type(
     __areas_.assign(1, 0.0);
   } else {
     __densities_.reserve(__b_.size() - 1);
-    for (size_t __i = 0; __i < __b_.size() - 1; ++__i, ++__f_w)
+    for (size_t __i = 0; __i < __b_.size() - 1; ++__i, (void)++__f_w)
       __densities_.push_back(*__f_w);
     __init();
   }

libcxx/include/__random/piecewise_linear_distribution.h

@@ -194,7 +194,7 @@ piecewise_linear_distribution<_RealType>::param_type::param_type(
     __areas_.assign(1, 0.0);
   } else {
     __densities_.reserve(__b_.size());
-    for (size_t __i = 0; __i < __b_.size(); ++__i, ++__f_w)
+    for (size_t __i = 0; __i < __b_.size(); ++__i, (void)++__f_w)
       __densities_.push_back(*__f_w);
     __init();
   }

libcxx/test/std/containers/sequences/deque/deque.cons/iter_iter.pass.cpp

@@ -33,7 +33,7 @@ void test(InputIterator f, InputIterator l) {
   assert(d.size() == static_cast<std::size_t>(std::distance(f, l)));
   assert(static_cast<std::size_t>(std::distance(d.begin(), d.end())) == d.size());
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(d));
-  for (const_iterator i = d.begin(), e = d.end(); i != e; ++i, ++f)
+  for (const_iterator i = d.begin(), e = d.end(); i != e; ++i, (void)++f)
     assert(*i == *f);
 }
 

libcxx/test/std/containers/sequences/deque/deque.cons/iter_iter_alloc.pass.cpp

@@ -34,7 +34,7 @@ void test(InputIterator f, InputIterator l, const Allocator& a) {
   assert(d.size() == static_cast<std::size_t>(std::distance(f, l)));
   assert(static_cast<std::size_t>(std::distance(d.begin(), d.end())) == d.size());
   LIBCPP_ASSERT(is_double_ended_contiguous_container_asan_correct(d));
-  for (const_iterator i = d.begin(), e = d.end(); i != e; ++i, ++f)
+  for (const_iterator i = d.begin(), e = d.end(); i != e; ++i, (void)++f)
     assert(*i == *f);
 }
 

libcxx/test/std/containers/sequences/vector.bool/construct_iter_iter.pass.cpp

@@ -24,7 +24,7 @@ TEST_CONSTEXPR_CXX20 void test(Iterator first, Iterator last) {
   C c(first, last);
   LIBCPP_ASSERT(c.__invariants());
   assert(c.size() == static_cast<std::size_t>(std::distance(first, last)));
-  for (typename C::const_iterator i = c.cbegin(), e = c.cend(); i != e; ++i, ++first)
+  for (typename C::const_iterator i = c.cbegin(), e = c.cend(); i != e; ++i, (void)++first)
     assert(*i == *first);
 }
 

libcxx/test/std/containers/sequences/vector.bool/construct_iter_iter_alloc.pass.cpp

@@ -25,7 +25,7 @@ TEST_CONSTEXPR_CXX20 void test(Iterator first, Iterator last, const typename C::
   C c(first, last, a);
   LIBCPP_ASSERT(c.__invariants());
   assert(c.size() == static_cast<std::size_t>(std::distance(first, last)));
-  for (typename C::const_iterator i = c.cbegin(), e = c.cend(); i != e; ++i, ++first)
+  for (typename C::const_iterator i = c.cbegin(), e = c.cend(); i != e; ++i, (void)++first)
     assert(*i == *first);
 }
 

libcxx/test/std/containers/sequences/vector/vector.cons/construct_iter_iter.pass.cpp

@@ -31,7 +31,7 @@ TEST_CONSTEXPR_CXX20 void test(Iterator first, Iterator last) {
     LIBCPP_ASSERT(c.__invariants());
     assert(c.size() == static_cast<std::size_t>(std::distance(first, last)));
     LIBCPP_ASSERT(is_contiguous_container_asan_correct(c));
-    for (typename C::const_iterator i = c.cbegin(), e = c.cend(); i != e; ++i, ++first)
+    for (typename C::const_iterator i = c.cbegin(), e = c.cend(); i != e; ++i, (void)++first)
       assert(*i == *first);
   }
   // Test with an empty range