Add C++17 uninitialized storage ops

Author: kjbracey

platform/cxxsupport/mstd_memory

@@ -23,13 +23,28 @@
  * - For ARM C 5, C++11/14 features:
  *   - std::align
  *   - std::addressof
+ *   - std::uninitialized_copy_n
  *   - std::unique_ptr, std::make_unique, std::default_delete
+ * - For all toolchains, C++17 backports:
+ *   - mstd::uninitialized_default_construct, mstd::uninitialized_value_construct
+ *   - mstd::uninitialized_move, mstd::uninitialized_move_n
+ *   - mstd::destroy_at, mstd::destroy, mstd::destroy_n
  */
 
 #include <memory>
 
 #include <mstd_type_traits>
 
+// Forward declarations
+namespace std
+{
+template <typename T1, typename T2>
+class pair;
+
+template <class Iterator>
+struct iterator_traits;
+}
+
 #ifdef __CC_ARM
 
 #include <cstddef> // size_t, ptrdiff_t
@@ -60,6 +75,19 @@ T *addressof(T &arg) noexcept
     return reinterpret_cast<T *>(const_cast<char *>(&reinterpret_cast<const volatile char &>(arg)));
 }
 
+// [uninitialized.copy] - ARMCC has pre-C++11 uninitialized_copy
+template <class InputIterator, class Size, class ForwardIterator>
+ForwardIterator uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result) {
+    for ( ; n > 0; ++result, (void) ++first, --n) {
+        ::new (static_cast<void*>(addressof(*result)))
+              typename std::iterator_traits<ForwardIterator>::value_type(*first);
+    }
+
+    return result;
+}
+
+// [uninitialized.fill] - ARMCC has pre-C++11 uninitialized_fill and uninitialized_fill_n
+
 // [unique.ptr]
 namespace impl
 {
@@ -496,12 +524,97 @@ bool operator>=(nullptr_t, const unique_ptr<T, D> &x) noexcept
 #endif // __CC_ARM
 
 namespace mstd {
+    using std::align;
     using std::allocator;
+    using std::addressof;
+
+    // [uninitialized.construct.default] (C++17)
+    template <class ForwardIterator, class Size>
+    void uninitialized_default_construct(ForwardIterator first, ForwardIterator last) {
+        for (; first != last; ++first) {
+            ::new (static_cast<void*>(addressof(*first)))
+                    typename std::iterator_traits<ForwardIterator>::value_type;
+        }
+    }
+
+    template <class ForwardIterator, class Size>
+    ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n) {
+        for (; n; ++first, --n) {
+            ::new (static_cast<void*>(addressof(*first)))
+                    typename std::iterator_traits<ForwardIterator>::value_type;
+        }
+
+        return first;
+    }
+
+    // [uninitialized.construct.value] (C++17)
+    template <class ForwardIterator, class Size>
+    void uninitialized_value_construct(ForwardIterator first, ForwardIterator last) {
+        for (; first != last; ++first) {
+            ::new (static_cast<void*>(addressof(*first)))
+                    typename std::iterator_traits<ForwardIterator>::value_type();
+        }
+    }
+
+    template <class ForwardIterator, class Size>
+    ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n) {
+        for (; n; ++first, --n) {
+            ::new (static_cast<void*>(addressof(*first)))
+                    typename std::iterator_traits<ForwardIterator>::value_type();
+        }
+
+        return first;
+    }
+
+    // [uninitialized.move] (C++17)
+    template <class InputIterator, class ForwardIterator>
+    ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result) {
+        for (; first != last; ++result, (void) ++first) {
+            ::new (static_cast<void*>(addressof(*result)))
+                  typename std::iterator_traits<ForwardIterator>::value_type(move(*first));
+        }
+
+        return result;
+    }
+
+    template <class InputIterator, class Size, class ForwardIterator>
+    std::pair<InputIterator, ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result) {
+        for ( ; n > 0; ++result, (void) ++first, --n) {
+            ::new (static_cast<void*>(addressof(*result)))
+                  typename std::iterator_traits<ForwardIterator>::value_type(std::move(*first));
+        }
+
+        return { first, result };
+    }
+
     using std::uninitialized_copy;
+    using std::uninitialized_copy_n;
     using std::uninitialized_fill;
     using std::uninitialized_fill_n;
-    using std::addressof;
-    using std::align;
+
+    // [specialized.destroy] (C++17)
+    template <class T>
+    void destroy_at(T *location)
+    {
+        location->~T();
+    }
+
+    template <class ForwardIterator>
+    void destroy(ForwardIterator first, ForwardIterator last)
+    {
+        for (; first != last; ++first) {
+            destroy_at(addressof(*first));
+        }
+    }
+
+    template <class ForwardIterator, class Size>
+    ForwardIterator destroy_n(ForwardIterator first, Size n)
+    {
+        for (; n > 0; (void)++first, --n) {
+            destroy_at(addressof(*first));
+        }
+        return first;
+    }
 
     using std::default_delete;
     using std::unique_ptr;