标准库标头 <new>

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C++
 
标准库头
通用工具
<any> (C++17)
<bitset>
<bit> (C++20)
<charconv> (C++17)
<expected> (C++23)
<format> (C++20)
<functional>
<optional> (C++17)
<stdbit.h> (C++26)
<tuple> (C++11)
<typeindex> (C++11)
<utility>
<variant> (C++17)
容器
<array> (C++11)
<deque>
<flat_map> (C++23)
<flat_set> (C++23)
<forward_list> (C++11)
<hive> (C++26)
<inplace_vector> (C++26)   
<list>
<map>
<mdspan> (C++23)
<queue>
<set>
<span> (C++20)
<stack>
<unordered_map> (C++11)
<unordered_set> (C++11)
<vector>
迭代器
<iterator>
范围
<generator> (C++23)
<ranges> (C++20)
 

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) [编辑]
(C++11)
 分配有非法长度的数组时抛出的异常
(类) [编辑]
(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) [编辑]

类型

 new 处理函数的函数指针类型
(typedef) [编辑]

标签

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

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) [编辑]

函数

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

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;