实验性库头文件 <experimental/any>

 

C++

编译器支持

自立实现与有宿主实现

语言

标准库

标准库标头

具名要求

功能特性测试宏 (C++20)

语言支持库

概念库 (C++20)

元编程库 (C++11)

诊断库

通用工具库

字符串库

容器库

迭代器库

范围库 (C++20)

算法库

数值库

本地化库

输入/输出库

文件系统库 (C++17)

正则表达式库 (C++11)

并发支持库 (C++11)

技术规范

符号索引

外部库

 

标准库标头

注：修订记号中的反斜杠 '/' 意味着此标头被弃用和/或被移除。

语言支持
<cstddef> <cstdlib> <version> (C++20) <limits> <climits>	<cfloat> <cstdint> (C++11) <stdfloat> (C++23) <new> <typeinfo>	<source_location> (C++20) <exception> <initializer_list> (C++11) <compare> (C++20)	<coroutine> (C++20) <csignal> <csetjmp> <cstdarg>
概念
<concepts> (C++20)
诊断
<stdexcept> <stacktrace> (C++23)	<cassert>	<cerrno>	<system_error> (C++11)
内存管理
<memory>	<memory_resource> (C++17)	<scoped_allocator> (C++11)
元编程
<type_traits> (C++11)	<ratio> (C++11)
通用工具
<utility> <tuple> (C++11) <optional> (C++17) <variant> (C++17)	<any> (C++17) <expected> (C++23) <bitset>	<functional> <typeindex> (C++11) <execution> (C++17)	<charconv> (C++17) <format> (C++20) <bit> (C++20)
字符串
<string_view> (C++17) <string>	<cctype> <cwctype>	<cstring> <cwchar>	<cuchar> (C++11)
容器
<array> (C++11) <deque> <forward_list> (C++11) <list>	<vector> <map> <set> <unordered_map> (C++11)	<unordered_set> (C++11) <queue> <stack> <flat_map> (C++23)	<flat_set> (C++23) <span> (C++20) <mdspan> (C++23)
迭代器
<iterator>
范围
<ranges> (C++20)	<generator> (C++23)
算法
<algorithm>	<execution>
数值
<cfenv> (C++11) <complex>	<random> (C++11) <valarray>	<cmath>	<numbers> (C++20)
日期时间
<chrono> (C++11)	<ctime>
本地化
<locale>	<clocale>	<codecvt> (C++11/17)
输入/输出
<iosfwd> <iostream> <ios> <streambuf>	<istream> <ostream> <iomanip> <print> (C++23)	<sstream> <spanstream> (C++23) <fstream> <syncstream> (C++20)	<filesystem> (C++17) <cstdio> <cinttypes> (C++11) <strstream> (C++98/)
正则表达式
<regex>
并发支持
<stop_token> (C++20) <thread> (C++11) <atomic> (C++11)	<stdatomic.h> (C++23) <mutex> (C++11) <shared_mutex> (C++14)	<condition_variable> (C++11)   <semaphore> (C++20) <latch> (C++20)	<barrier> (C++20) <future> (C++11)
C 兼容
<cstdbool> (C++11/17/20)   <ccomplex> (C++11/17/20)	<ctgmath> (C++11/17/20)	<cstdalign> (C++11/17/20)	<ciso646> (C++20 前)

 

实验性库头文件

文件系统 TS
<experimental/filesystem>
并行 TS (v1, v2)
<experimental/algorithm> <experimental/execution_policy> <experimental/exception_list>	<experimental/numeric> <experimental/simd> <experimental/task_block>
库基础 TS (v1, v2, v3)
<experimental/algorithm> <experimental/any> <experimental/array> <experimental/chrono> <experimental/deque> <experimental/forward_list> <experimental/functional> <experimental/future> <experimental/iterator> <experimental/list> <experimental/map> <experimental/memory> <experimental/memory_resource> <experimental/numeric> <experimental/optional> <experimental/propagate_const>	<experimental/random> <experimental/ratio> <experimental/regex> <experimental/scope> <experimental/set> <experimental/source_location> <experimental/string> <experimental/string_view> <experimental/system_error> <experimental/tuple> <experimental/type_traits> <experimental/unordered_map> <experimental/unordered_set> <experimental/utility> <experimental/vector>
并发 TS
<experimental/atomic> <experimental/barrier>	<experimental/future> <experimental/latch>
范围 TS
<experimental/ranges/algorithm> <experimental/ranges/concepts> <experimental/ranges/functional>     <experimental/ranges/iterator>	<experimental/ranges/random> <experimental/ranges/tuple> <experimental/ranges/type_traits> <experimental/ranges/utility>
协程 TS
<experimental/coroutine>
网络 TS
<experimental/buffer> <experimental/executor> <experimental/internet> <experimental/io_context>	<experimental/net> <experimental/netfwd> <experimental/socket> <experimental/timer>
反射 TS
<experimental/reflect>

 

此头文件是库基础 TS (v1, v2) 的一部分。

类

名字	描述
bad_any_cast (库基础 TS)	由失败的 any_cast 所抛出的异常。 (类)
any (库基础 TS)	保有满足 ValueType 要求的任意类型的实例的对象。 (类)

函数

swap	交换两个 any 实例 (函数)
any_cast	对被容纳对象的类型安全访问 (函数模板)

概要

namespace std {
namespace experimental {
inline namespace fundamentals_v1 {
 
  class bad_any_cast : public bad_cast
  {
  public:
    virtual const char* what() const noexcept;
  };
 
  class any
  {
  public:
    // 6.3.1，any 构造/析构
    any() noexcept;
 
    any(const any& other);
    any(any&& x) noexcept;
 
    template <class ValueType>
        any(ValueType&& value);
 
    ~any();
 
    // 6.3.2，any 赋值
    any& operator=(const any& rhs);
    any& operator=(any&& rhs) noexcept;
 
    template <class ValueType>
      any& operator=(ValueType&& rhs);
 
    // 6.3.3，any 修改函数
    void clear() noexcept;
    void swap(any& rhs) noexcept;
 
    // 6.3.4，any 探察函数
    bool empty() const noexcept;
    const type_info& type() const noexcept;
  };
 
  // 6.4，非成员函数
  void swap(any& x, any& y) noexcept;
 
  template<class ValueType>
    ValueType any_cast(const any& operand);
  template<class ValueType>
    ValueType any_cast(any& operand);
  template<class ValueType>
    ValueType any_cast(any&& operand);
 
  template<class ValueType>
    const ValueType* any_cast(const any* operand) noexcept;
  template<class ValueType>
    ValueType* any_cast(any* operand) noexcept;
 
} // namespace fundamentals_v1
} // namespace experimental
} // namespace std