llvm-project/libcxx/test/support/test_constexpr_container.h
Arthur O'Dwyer 06e2b737aa [libc++] [P1032] Misc constexpr bits in <iterator>, <string_view>, <tuple>, <utility>.
This completes the implementation of P1032's changes to <iterator>,
<string_view>, <tuple>, and <utility> in C++20.
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1032r1.html

Drive-by fix a couple of unintended rvalues in "*iterators*/*.fail.cpp".

Differential Revision: https://reviews.llvm.org/D96385
2021-03-25 10:34:35 -04:00

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1.8 KiB
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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef SUPPORT_TEST_CONSTEXPR_CONTAINER_H
#define SUPPORT_TEST_CONSTEXPR_CONTAINER_H
// A dummy container with enough constexpr support to test the standard
// insert iterators, such as `back_insert_iterator`.
#include <algorithm>
#include <cassert>
#include <utility>
#include "test_macros.h"
#if TEST_STD_VER >= 14
template<class T, int N>
class ConstexprFixedCapacityDeque {
T data_[N];
int size_ = 0;
public:
using value_type = T;
using iterator = T *;
using const_iterator = T const *;
constexpr ConstexprFixedCapacityDeque() = default;
constexpr iterator begin() { return data_; }
constexpr iterator end() { return data_ + size_; }
constexpr const_iterator begin() const { return data_; }
constexpr const_iterator end() const { return data_ + size_; }
constexpr size_t size() const { return size_; }
constexpr const T& front() const { assert(size_ >= 1); return data_[0]; }
constexpr const T& back() const { assert(size_ >= 1); return data_[size_-1]; }
constexpr iterator insert(const_iterator pos, T t) {
int i = (pos - data_);
if (i != size_) {
std::move_backward(data_ + i, data_ + size_, data_ + size_ + 1);
}
data_[i] = std::move(t);
size_ += 1;
return data_ + i;
}
constexpr void push_back(T t) { insert(end(), std::move(t)); }
constexpr void push_front(T t) { insert(begin(), std::move(t)); }
};
#endif // TEST_STD_VER >= 14
#endif // SUPPORT_TEST_CONSTEXPR_CONTAINER_H