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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 TEST_SUPPORT_INCREASING_ALLOCATOR_H
#define TEST_SUPPORT_INCREASING_ALLOCATOR_H
#include <cstddef>
#include <memory>
#include "test_macros.h"
// The increasing_allocator is a custom allocator that enforces an increasing minimum allocation size,
// ensuring that it allocates an increasing amount of memory, possibly exceeding the requested amount.
// This unique behavior is particularly useful for testing the shrink_to_fit functionality in std::vector,
// vector<bool>, and std::basic_string, ensuring that shrink_to_fit does not increase the capacity of
// the allocated memory.
template <typename T>
struct increasing_allocator {
using value_type = T;
std::size_t min_elements = 1000;
increasing_allocator() = default;
template <typename U>
TEST_CONSTEXPR_CXX20 increasing_allocator(const increasing_allocator<U>& other) TEST_NOEXCEPT
: min_elements(other.min_elements) {}
#if TEST_STD_VER >= 23
TEST_CONSTEXPR_CXX23 std::allocation_result<T*> allocate_at_least(std::size_t n) {
if (n < min_elements)
n = min_elements;
min_elements += 1000;
return std::allocator<T>{}.allocate_at_least(n);
}
#endif // TEST_STD_VER >= 23
TEST_CONSTEXPR_CXX20 T* allocate(std::size_t n) { return std::allocator<T>().allocate(n); }
TEST_CONSTEXPR_CXX20 void deallocate(T* p, std::size_t n) TEST_NOEXCEPT { std::allocator<T>().deallocate(p, n); }
};
template <typename T, typename U>
TEST_CONSTEXPR_CXX20 bool operator==(increasing_allocator<T>, increasing_allocator<U>) TEST_NOEXCEPT {
return true;
}
#endif // TEST_SUPPORT_INCREASING_ALLOCATOR_H
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