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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
//
//===----------------------------------------------------------------------===//
// <memory>
// shared_ptr
// template<class T, class A, class... Args>
// shared_ptr<T> allocate_shared(const A& a, Args&&... args);
// This test checks that allocator_traits::construct and allocator_traits::destroy
// are used in allocate_shared as requested for the resolution of LWG2070. Note
// that LWG2070 was resolved by P0674R1 (which is a C++20 paper), but we implement
// LWG issue resolutions as DRs per our policy.
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <memory>
#include <new>
#include <utility>
#include "test_macros.h"
static bool construct_called = false;
static bool destroy_called = false;
static unsigned allocator_id = 0;
template <class T>
struct MyAllocator {
public:
typedef T value_type;
typedef T* pointer;
unsigned id = 0;
MyAllocator() = default;
MyAllocator(int i) : id(i) {}
template <class U>
MyAllocator(MyAllocator<U> const& other) : id(other.id) {}
pointer allocate(std::ptrdiff_t n) {
return pointer(static_cast<T*>(::operator new(n * sizeof(T))));
}
void deallocate(pointer p, std::ptrdiff_t) { return ::operator delete(p); }
template <typename ...Args>
void construct(T* p, Args&& ...args) {
construct_called = true;
destroy_called = false;
allocator_id = id;
::new (p) T(std::forward<Args>(args)...);
}
void destroy(T* p) {
construct_called = false;
destroy_called = true;
allocator_id = id;
p->~T();
}
};
struct Private;
class Factory {
public:
static std::shared_ptr<Private> allocate();
};
template <class T>
struct FactoryAllocator;
struct Private {
int id;
private:
friend FactoryAllocator<Private>;
Private(int i) : id(i) {}
~Private() {}
};
template <class T>
struct FactoryAllocator : std::allocator<T> {
FactoryAllocator() = default;
template <class T1>
FactoryAllocator(FactoryAllocator<T1>) {}
template <class T1>
struct rebind {
typedef FactoryAllocator<T1> other;
};
void construct(void* p, int id) { ::new (p) Private(id); }
void destroy(Private* p) { p->~Private(); }
};
std::shared_ptr<Private> Factory::allocate() {
FactoryAllocator<Private> factory_alloc;
return std::allocate_shared<Private>(factory_alloc, 42);
}
struct mchar {
char c;
};
struct Foo {
int val;
Foo(int v) : val(v) {}
Foo(Foo a, Foo b) : val(a.val + b.val) {}
};
void test_aligned(void* p, std::size_t align) {
assert(reinterpret_cast<std::uintptr_t>(p) % align == 0);
}
int main(int, char**) {
{
std::shared_ptr<int> p = std::allocate_shared<int>(MyAllocator<int>());
assert(construct_called);
}
assert(destroy_called);
{
std::shared_ptr<Foo> p =
std::allocate_shared<Foo>(MyAllocator<Foo>(), Foo(42), Foo(100));
assert(construct_called);
assert(p->val == 142);
}
assert(destroy_called);
{ // Make sure allocator is copied.
std::shared_ptr<int> p = std::allocate_shared<int>(MyAllocator<int>(3));
assert(allocator_id == 3);
allocator_id = 0;
}
assert(allocator_id == 3);
{
std::shared_ptr<int> p = std::allocate_shared<int>(MyAllocator<int>(), 42);
assert(construct_called);
assert(*p == 42);
}
assert(destroy_called);
{ // Make sure allocator is properly re-bound.
std::shared_ptr<int> p =
std::allocate_shared<int>(MyAllocator<mchar>(), 42);
assert(construct_called);
assert(*p == 42);
}
assert(destroy_called);
{
// Make sure that we call the correct allocator::construct. Private has a private constructor
// so the construct method must be called on its friend Factory's allocator
// (Factory::Allocator).
std::shared_ptr<Private> p = Factory().allocate();
assert(p->id == 42);
}
#if TEST_STD_VER >= 11
{
struct Bar {
std::max_align_t y;
};
std::shared_ptr<Bar> p;
test_aligned(p.get(), alignof(Bar));
}
#endif
return 0;
}
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