1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef TEST_STD_CONTAINERS_VIEWS_MDSPAN_MINIMAL_ELEMENT_TYPE_H
10#define TEST_STD_CONTAINERS_VIEWS_MDSPAN_MINIMAL_ELEMENT_TYPE_H
11
12#include <memory>
13#include <type_traits>
14
15// Idiosyncratic element type for mdspan
16// Make sure we don't assume copyable, default constructible, movable etc.
17struct MinimalElementType {
18 int val;
19 constexpr MinimalElementType() = delete;
20 constexpr MinimalElementType(const MinimalElementType&) = delete;
21 constexpr explicit MinimalElementType(int v) noexcept : val(v){}
22 constexpr MinimalElementType& operator=(const MinimalElementType&) = delete;
23};
24
25// Helper class to create pointer to MinimalElementType
26template<class T, size_t N>
27struct ElementPool {
28 constexpr ElementPool() {
29 ptr_ = std::allocator<std::remove_const_t<T>>().allocate(N);
30 for (int i = 0; i != N; ++i)
31 std::construct_at(ptr_ + i, 42);
32 }
33
34 constexpr T* get_ptr() { return ptr_; }
35
36 constexpr ~ElementPool() {
37 for (int i = 0; i != N; ++i)
38 std::destroy_at(ptr_ + i);
39 std::allocator<std::remove_const_t<T>>().deallocate(ptr_, N);
40 }
41
42private:
43 std::remove_const_t<T>* ptr_;
44};
45
46#endif // TEST_STD_CONTAINERS_VIEWS_MDSPAN_MINIMAL_ELEMENT_TYPE_H
47

source code of libcxx/test/std/containers/views/mdspan/MinimalElementType.h