Merge pull request #11076 from kjbracey-arm/mstd

ARMC5 <array> extensions

Author: Seppo Takalo

platform/cxxsupport/TOOLCHAIN_ARMC5/array

@@ -19,8 +19,10 @@
 
 #include <initializer_list> // required by standard
 
+#include <_move.h>
 #include <cstddef> // size_t, ptrdiff_t
 #include <algorithm> // fill and swap_ranges
+#include <type_traits> // integral_constant
 
 namespace std {
 template <typename>
@@ -30,7 +32,7 @@ struct reverse_iterator;
 template <typename _TypeT, size_t _Size>
 struct array {
     // [array.overview]
-    _TypeT _C_elem[_Size];
+    _TypeT _C_elem[_Size != 0 ? _Size : 1];
 
     using value_type = _TypeT;
     using size_type = size_t;
@@ -44,7 +46,8 @@ struct array {
     using reverse_iterator = std::reverse_iterator<iterator>;
     using const_reverse_iterator = std::reverse_iterator<const_iterator>;
     // [array.size]
-    constexpr size_type size() const noexcept
+    // ARMC5 complains "a constexpr member function is only permitted in a literal class type"
+    /*constexpr*/ size_type size() const noexcept
     {
         return _Size;
     }
@@ -101,11 +104,11 @@ struct array {
     {
         return _C_elem[_Size - 1];
     }
-    constexpr bool empty() const noexcept
+    /*constexpr*/ bool empty() const noexcept
     {
         return false;
     }
-    constexpr size_type max_size() const noexcept
+    /*constexpr*/ size_type max_size() const noexcept
     {
         return _Size;
     }
@@ -159,13 +162,90 @@ struct array {
     }
 };
 
+template <typename _TypeT, size_t _Size>
+bool operator==(const array<_TypeT, _Size> &__x, const array<_TypeT, _Size> &__y)
+{
+    return equal(__x.begin(), __x.end(), __y.begin());
+}
+
+template <typename _TypeT, size_t _Size>
+bool operator!=(const array<_TypeT, _Size> &__x, const array<_TypeT, _Size> &__y)
+{
+    return !(__x == __y);
+}
+
+template <typename _TypeT, size_t _Size>
+bool operator<(const array<_TypeT, _Size> &__x, const array<_TypeT, _Size> &__y)
+{
+    return lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
+}
+
+template <typename _TypeT, size_t _Size>
+bool operator>(const array<_TypeT, _Size> &__x, const array<_TypeT, _Size> &__y)
+{
+    return __y < __x;
+}
+
+template <typename _TypeT, size_t _Size>
+bool operator<=(const array<_TypeT, _Size> &__x, const array<_TypeT, _Size> &__y)
+{
+    return !(__x > __y);
+}
+
+template <typename _TypeT, size_t _Size>
+bool operator>=(const array<_TypeT, _Size> &__x, const array<_TypeT, _Size> &__y)
+{
+    return !(__x < __y);
+}
+
 // [array.special]
-template <class _TypeT, size_t _Size>
+template <typename _TypeT, size_t _Size>
 void swap(array<_TypeT, _Size> &__x, array<_TypeT, _Size> &__y)
 {
     __x.swap(__y);
 }
 
+// [array.tuple]
+template <typename>
+struct tuple_size;
+
+template <typename _TypeT, size_t _Size>
+struct tuple_size<array<_TypeT, _Size>> : integral_constant<size_t, _Size> { };
+
+template <size_t, typename>
+struct tuple_element;
+
+template <size_t _Idx, typename _TypeT, size_t _Size>
+struct tuple_element<_Idx, array<_TypeT, _Size>> : type_identity<_TypeT> {
+    static_assert(_Idx < _Size, "array index out of bounds");
+};
+
+template <size_t _Idx, typename _TypeT, size_t _Size>
+constexpr _TypeT &get(array<_TypeT, _Size> &__a) noexcept
+{
+    static_assert(_Idx < _Size, "array index out of bounds");
+    return __a._C_elem[_Idx];
+}
+
+template <size_t _Idx, typename _TypeT, size_t _Size>
+_TypeT &&get(array<_TypeT, _Size> &&__a) noexcept
+{
+    return std::move(get<_Idx>(__a));
+}
+
+template <size_t _Idx, typename _TypeT, size_t _Size>
+constexpr const _TypeT &get(const array<_TypeT, _Size> &__a) noexcept
+{
+    static_assert(_Idx < _Size, "array index out of bounds");
+    return __a._C_elem[_Idx];
+}
+
+template <size_t _Idx, typename _TypeT, size_t _Size>
+const _TypeT &&get(const array<_TypeT, _Size> &&__a) noexcept
+{
+    return std::move(get<_Idx>(__a));
+}
+
 } // namespace std
 
 #endif /* __array */