Misc constexpr

stl/inc/array

@@ -437,11 +437,11 @@ public:
     }
 #endif // _HAS_TR1_NAMESPACE
 
-    void fill(const _Ty& _Value) {
+    _CONSTEXPR20 void fill(const _Ty& _Value) {
         _STD fill_n(_Elems, _Size, _Value);
     }
 
-    void swap(array& _Other) noexcept(_Is_nothrow_swappable<_Ty>::value) {
+    _CONSTEXPR20 void swap(array& _Other) noexcept(_Is_nothrow_swappable<_Ty>::value) {
         _Swap_ranges_unchecked(_Elems, _Elems + _Size, _Other._Elems);
     }
 
@@ -618,9 +618,9 @@ public:
     _DEPRECATE_TR1_NAMESPACE void assign(const _Ty&) {}
 #endif // _HAS_TR1_NAMESPACE
 
-    void fill(const _Ty&) {}
+    _CONSTEXPR20 void fill(const _Ty&) {}
 
-    void swap(array&) noexcept {}
+    _CONSTEXPR20 void swap(array&) noexcept {}
 
     _NODISCARD _CONSTEXPR17 iterator begin() noexcept {
         return iterator{};
@@ -770,7 +770,7 @@ public:
 };
 
 template <class _Ty, size_t _Size, enable_if_t<_Size == 0 || _Is_swappable<_Ty>::value, int> = 0>
-void swap(array<_Ty, _Size>& _Left, array<_Ty, _Size>& _Right) noexcept(noexcept(_Left.swap(_Right))) {
+_CONSTEXPR20 void swap(array<_Ty, _Size>& _Left, array<_Ty, _Size>& _Right) noexcept(noexcept(_Left.swap(_Right))) {
     return _Left.swap(_Right);
 }
 

stl/inc/functional

@@ -1612,7 +1612,7 @@ struct _Global_delete {
 
 // CLASS TEMPLATE default_searcher
 template <class _FwdItHaystack, class _FwdItPat, class _Pred_eq>
-pair<_FwdItHaystack, _FwdItHaystack> _Search_pair_unchecked(_FwdItHaystack _First1, _FwdItHaystack _Last1,
+_CONSTEXPR20 pair<_FwdItHaystack, _FwdItHaystack> _Search_pair_unchecked(_FwdItHaystack _First1, _FwdItHaystack _Last1,
     _FwdItPat _First2, _FwdItPat _Last2, _Pred_eq& _Eq, forward_iterator_tag, forward_iterator_tag) {
     // find first [_First2, _Last2) satisfying _Eq, arbitrary iterators
     for (;; ++_First1) { // loop until match or end of a sequence
@@ -1634,7 +1634,7 @@ pair<_FwdItHaystack, _FwdItHaystack> _Search_pair_unchecked(_FwdItHaystack _Firs
 }
 
 template <class _FwdItHaystack, class _FwdItPat, class _Pred_eq>
-pair<_FwdItHaystack, _FwdItHaystack> _Search_pair_unchecked(_FwdItHaystack _First1, _FwdItHaystack _Last1,
+_CONSTEXPR20 pair<_FwdItHaystack, _FwdItHaystack> _Search_pair_unchecked(_FwdItHaystack _First1, _FwdItHaystack _Last1,
     _FwdItPat _First2, _FwdItPat _Last2, _Pred_eq& _Eq, random_access_iterator_tag, random_access_iterator_tag) {
     // find first [_First2, _Last2) satisfying _Eq, random-access iterators
     _Iter_diff_t<_FwdItHaystack> _Count1 = _Last1 - _First1;
@@ -1659,14 +1659,15 @@ pair<_FwdItHaystack, _FwdItHaystack> _Search_pair_unchecked(_FwdItHaystack _Firs
 template <class _FwdItPat, class _Pred_eq = equal_to<>>
 class default_searcher { // functor to search haystacks for needles
 public:
-    default_searcher(_FwdItPat _First, _FwdItPat _Last, _Pred_eq _Eq = _Pred_eq())
+    _CONSTEXPR20 default_searcher(_FwdItPat _First, _FwdItPat _Last, _Pred_eq _Eq = _Pred_eq())
         : _Data{_One_then_variadic_args_t{}, _STD move(_Eq), pair<_FwdItPat, _FwdItPat>{_First, _Last}} {
         const auto& _Pat = _Data._Myval2;
         _Adl_verify_range(_Pat.first, _Pat.second);
     }
 
     template <class _FwdItHaystack>
-    _NODISCARD pair<_FwdItHaystack, _FwdItHaystack> operator()(_FwdItHaystack _First, _FwdItHaystack _Last) const {
+    _NODISCARD _CONSTEXPR20 pair<_FwdItHaystack, _FwdItHaystack> operator()(
+        _FwdItHaystack _First, _FwdItHaystack _Last) const {
         // search [_First, _Last) for the searcher's pattern
         _Adl_verify_range(_First, _Last);
         const auto& _Eq  = _Data._Get_first();

stl/inc/iterator

@@ -38,27 +38,28 @@ public:
     using difference_type = void;
 #endif // __cpp_lib_concepts
 
-    explicit back_insert_iterator(_Container& _Cont) noexcept /* strengthened */ : container(_STD addressof(_Cont)) {}
+    _CONSTEXPR20 explicit back_insert_iterator(_Container& _Cont) noexcept /* strengthened */
+        : container(_STD addressof(_Cont)) {}
 
-    back_insert_iterator& operator=(const typename _Container::value_type& _Val) {
+    _CONSTEXPR20 back_insert_iterator& operator=(const typename _Container::value_type& _Val) {
         container->push_back(_Val);
         return *this;
     }
 
-    back_insert_iterator& operator=(typename _Container::value_type&& _Val) {
+    _CONSTEXPR20 back_insert_iterator& operator=(typename _Container::value_type&& _Val) {
         container->push_back(_STD move(_Val));
         return *this;
     }
 
-    _NODISCARD back_insert_iterator& operator*() noexcept /* strengthened */ {
+    _NODISCARD _CONSTEXPR20 back_insert_iterator& operator*() noexcept /* strengthened */ {
         return *this;
     }
 
-    back_insert_iterator& operator++() noexcept /* strengthened */ {
+    _CONSTEXPR20 back_insert_iterator& operator++() noexcept /* strengthened */ {
         return *this;
     }
 
-    back_insert_iterator operator++(int) noexcept /* strengthened */ {
+    _CONSTEXPR20 back_insert_iterator operator++(int) noexcept /* strengthened */ {
         return *this;
     }
 
@@ -68,7 +69,7 @@ protected:
 
 // FUNCTION TEMPLATE back_inserter
 template <class _Container>
-_NODISCARD back_insert_iterator<_Container> back_inserter(_Container& _Cont) noexcept /* strengthened */ {
+_NODISCARD _CONSTEXPR20 back_insert_iterator<_Container> back_inserter(_Container& _Cont) noexcept /* strengthened */ {
     // return a back_insert_iterator
     return back_insert_iterator<_Container>(_Cont);
 }
@@ -92,27 +93,28 @@ public:
     using difference_type = void;
 #endif // __cpp_lib_concepts
 
-    explicit front_insert_iterator(_Container& _Cont) : container(_STD addressof(_Cont)) {}
+    _CONSTEXPR20 explicit front_insert_iterator(_Container& _Cont) : container(_STD addressof(_Cont)) {}
 
-    front_insert_iterator& operator=(const typename _Container::value_type& _Val) { // push value into container
+    _CONSTEXPR20 front_insert_iterator& operator=(const typename _Container::value_type& _Val) {
+        // push value into container
         container->push_front(_Val);
         return *this;
     }
 
-    front_insert_iterator& operator=(typename _Container::value_type&& _Val) { // push value into container
+    _CONSTEXPR20 front_insert_iterator& operator=(typename _Container::value_type&& _Val) { // push value into container
         container->push_front(_STD move(_Val));
         return *this;
     }
 
-    _NODISCARD front_insert_iterator& operator*() { // pretend to return designated value
+    _NODISCARD _CONSTEXPR20 front_insert_iterator& operator*() { // pretend to return designated value
         return *this;
     }
 
-    front_insert_iterator& operator++() { // pretend to preincrement
+    _CONSTEXPR20 front_insert_iterator& operator++() { // pretend to preincrement
         return *this;
     }
 
-    front_insert_iterator operator++(int) { // pretend to postincrement
+    _CONSTEXPR20 front_insert_iterator operator++(int) { // pretend to postincrement
         return *this;
     }
 
@@ -122,7 +124,7 @@ protected:
 
 // FUNCTION TEMPLATE front_inserter
 template <class _Container>
-_NODISCARD front_insert_iterator<_Container> front_inserter(_Container& _Cont) {
+_NODISCARD _CONSTEXPR20 front_insert_iterator<_Container> front_inserter(_Container& _Cont) {
     return front_insert_iterator<_Container>(_Cont);
 }
 
@@ -146,32 +148,32 @@ public:
     using difference_type = void;
 #endif // __cpp_lib_concepts
 
-    insert_iterator(_Container& _Cont, typename _Container::iterator _Where)
+    _CONSTEXPR20 insert_iterator(_Container& _Cont, typename _Container::iterator _Where)
         : container(_STD addressof(_Cont)), iter(_Where) {}
 
-    insert_iterator& operator=(
+    _CONSTEXPR20 insert_iterator& operator=(
         const typename _Container::value_type& _Val) { // insert into container and increment stored iterator
         iter = container->insert(iter, _Val);
         ++iter;
         return *this;
     }
 
-    insert_iterator& operator=(typename _Container::value_type&& _Val) { // push value into container
+    _CONSTEXPR20 insert_iterator& operator=(typename _Container::value_type&& _Val) { // push value into container
 
         iter = container->insert(iter, _STD move(_Val));
         ++iter;
         return *this;
     }
 
-    _NODISCARD insert_iterator& operator*() { // pretend to return designated value
+    _NODISCARD _CONSTEXPR20 insert_iterator& operator*() { // pretend to return designated value
         return *this;
     }
 
-    insert_iterator& operator++() { // pretend to preincrement
+    _CONSTEXPR20 insert_iterator& operator++() { // pretend to preincrement
         return *this;
     }
 
-    insert_iterator& operator++(int) { // pretend to postincrement
+    _CONSTEXPR20 insert_iterator& operator++(int) { // pretend to postincrement
         return *this;
     }
 
@@ -182,7 +184,7 @@ protected:
 
 // FUNCTION TEMPLATE inserter
 template <class _Container>
-_NODISCARD insert_iterator<_Container> inserter(_Container& _Cont, typename _Container::iterator _Where) {
+_NODISCARD _CONSTEXPR20 insert_iterator<_Container> inserter(_Container& _Cont, typename _Container::iterator _Where) {
     return insert_iterator<_Container>(_Cont, _Where);
 }