标准库标头 <new>

< cpp‎ | header


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。

类
内存分配失败时抛出的异常
(类)
(C++11)
 在分配有非法长度的数组时抛出的异常
(类)
(C++17)
 用于向带对齐分配及解分配函数传递对齐值的类型
(枚举)

类型
new 处理函数的函数指针类型
(typedef)

标签
用于选择不抛出分配函数 的标签
(常量)
(C++20)
 用于选择 operator delete 的销毁 delete 重载的标签
(标签)

常量
(C++17)
 避免假共享的最小偏移
促使真共享的最大偏移
(常量)

函数
分配函数
(函数)
解分配函数
(函数)
(C++11)
 获得当前的 new 处理函数
(函数)
注册一个 new 处理函数
(函数)
(C++17)
 指针优化屏障
(函数模板)

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;