[libc++] Add missing iterator requirement checks in the PSTL (#88127)

Also add tests for those, and add a few missing requirements to testing
iterators in the test suite.

2 files changed, 9 insertions, 0 deletions

diff --git a/libcxx/include/__numeric/pstl_reduce.h b/libcxx/include/__numeric/pstl_reduce.h
index f9f666c..d678b94 100644
--- a/libcxx/include/__numeric/pstl_reduce.h
+++ b/libcxx/include/__numeric/pstl_reduce.h
@@ -12,6 +12,7 @@
 #include <__algorithm/pstl_frontend_dispatch.h>
 #include <__config>
 #include <__functional/identity.h>
+#include <__iterator/cpp17_iterator_concepts.h>
 #include <__iterator/iterator_traits.h>
 #include <__numeric/pstl_transform_reduce.h>
 #include <__type_traits/is_execution_policy.h>
@@ -66,6 +67,7 @@ reduce(_ExecutionPolicy&& __policy,
        _ForwardIterator __last,
        _Tp __init,
        _BinaryOperation __op = {}) {
+  _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator, "reduce requires ForwardIterators");
   auto __res = std::__reduce(__policy, std::move(__first), std::move(__last), std::move(__init), std::move(__op));
   if (!__res)
     std::__throw_bad_alloc();
@@ -94,6 +96,7 @@ template <class _ExecutionPolicy,
           enable_if_t<is_execution_policy_v<_RawPolicy>, int> = 0>
 _LIBCPP_HIDE_FROM_ABI __iter_value_type<_ForwardIterator>
 reduce(_ExecutionPolicy&& __policy, _ForwardIterator __first, _ForwardIterator __last) {
+  _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator, "reduce requires ForwardIterators");
   auto __res = std::__reduce(__policy, std::move(__first), std::move(__last));
   if (!__res)
     std::__throw_bad_alloc();
diff --git a/libcxx/include/__numeric/pstl_transform_reduce.h b/libcxx/include/__numeric/pstl_transform_reduce.h
index 07ecf0d..2d2621d 100644
--- a/libcxx/include/__numeric/pstl_transform_reduce.h
+++ b/libcxx/include/__numeric/pstl_transform_reduce.h
@@ -13,6 +13,7 @@
 #include <__algorithm/pstl_frontend_dispatch.h>
 #include <__config>
 #include <__functional/operations.h>
+#include <__iterator/cpp17_iterator_concepts.h>
 #include <__numeric/transform_reduce.h>
 #include <__type_traits/is_execution_policy.h>
 #include <__utility/move.h>
@@ -72,6 +73,8 @@ _LIBCPP_HIDE_FROM_ABI _Tp transform_reduce(
     _Tp __init,
     _BinaryOperation1 __reduce,
     _BinaryOperation2 __transform) {
+  _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator1, "transform_reduce requires ForwardIterators");
+  _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator2, "transform_reduce requires ForwardIterators");
   auto __res = std::__transform_reduce(
       __policy,
       std::move(__first1),
@@ -99,6 +102,8 @@ _LIBCPP_HIDE_FROM_ABI _Tp transform_reduce(
     _ForwardIterator1 __last1,
     _ForwardIterator2 __first2,
     _Tp __init) {
+  _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator1, "transform_reduce requires ForwardIterators");
+  _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator2, "transform_reduce requires ForwardIterators");
   return std::transform_reduce(__policy, __first1, __last1, __first2, __init, plus{}, multiplies{});
 }
 
@@ -140,6 +145,7 @@ _LIBCPP_HIDE_FROM_ABI _Tp transform_reduce(
     _Tp __init,
     _BinaryOperation __reduce,
     _UnaryOperation __transform) {
+  _LIBCPP_REQUIRE_CPP17_FORWARD_ITERATOR(_ForwardIterator, "transform_reduce requires ForwardIterators");
   auto __res = std::__transform_reduce(
       __policy, std::move(__first), std::move(__last), std::move(__init), std::move(__reduce), std::move(__transform));
   if (!__res)