标准库标头 <new>
来自cppreference.com
此头文件是动态内存管理库的一部分，特别是它提供低层内存管理特性。
概要
namespace std {
// 存储分配错误
class bad_alloc;
class bad_array_new_length;
struct destroying_delete_t {
explicit destroying_delete_t() = default;
};
inline constexpr destroying_delete_t destroying_delete{};
// 全局 operator new 控制
enum class align_val_t : size_t {};
struct nothrow_t { explicit nothrow_t() = default; };
extern const nothrow_t nothrow;
using new_handler = void (*)();
new_handler get_new_handler() noexcept;
new_handler set_new_handler(new_handler new_p) noexcept;
// 指针优化屏障
template<class T> constexpr T* launder(T* p) noexcept;
// 硬件干涉大小
inline constexpr size_t hardware_destructive_interference_size = /* 由实现定义 */;
inline constexpr size_t hardware_constructive_interference_size = /* 由实现定义 */;
}
// 存储分配与解分配
void* operator new(std::size_t size);
void* operator new(std::size_t size, std::align_val_t alignment);
void* operator new(std::size_t size, const std::nothrow_t&) noexcept;
void* operator new(std::size_t size, std::align_val_t alignment,
const std::nothrow_t&) noexcept;
void operator delete(void* ptr) noexcept;
void operator delete(void* ptr, std::size_t size) noexcept;
void operator delete(void* ptr, std::align_val_t alignment) noexcept;
void operator delete(void* ptr, std::size_t size, std::align_val_t alignment) noexcept;
void operator delete(void* ptr, const std::nothrow_t&) noexcept;
void operator delete(void* ptr, std::align_val_t alignment,
const std::nothrow_t&) noexcept;
void* operator new[](std::size_t size);
void* operator new[](std::size_t size, std::align_val_t alignment);
void* operator new[](std::size_t size, const std::nothrow_t&) noexcept;
void* operator new[](std::size_t size, std::align_val_t alignment,
const std::nothrow_t&) noexcept;
void operator delete[](void* ptr) noexcept;
void operator delete[](void* ptr, std::size_t size) noexcept;
void operator delete[](void* ptr, std::align_val_t alignment) noexcept;
void operator delete[](void* ptr, std::size_t size, std::align_val_t alignment) noexcept;
void operator delete[](void* ptr, const std::nothrow_t&) noexcept;
void operator delete[](void* ptr, std::align_val_t alignment,
const std::nothrow_t&) noexcept;
constexpr void* operator new (std::size_t size, void* ptr) noexcept;
constexpr void* operator new[](std::size_t size, void* ptr) noexcept;
void operator delete (void* ptr, void*) noexcept;
void operator delete[](void* ptr, void*) noexcept;