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)

诊断库

内存管理库

元编程库 (C++11)

通用工具库

容器库

迭代器库

范围库 (C++20)

算法库

字符串库

文本处理库

数值库

日期和时间库

输入/输出库

文件系统库 (C++17)

并发支持库 (C++11)

执行控制库 (C++26)

技术规范

符号索引

外部库

 

标准库头

语言支持 <cfloat> <climits> <compare> (C++20) <contracts> (C++26) <coroutine> (C++20) <csetjmp> <csignal> <cstdarg> <cstddef> <cstdint> (C++11) <cstdlib> <exception> <initializer_list> (C++11)    <limits> <new> <source_location> (C++20) <stdfloat> (C++23) <typeinfo> <version> (C++20) 概念 <concepts> (C++20) 诊断 <cassert> <cerrno> <debugging> (C++26) <stacktrace> (C++23) <stdexcept> <system_error> (C++11) 内存管理 <memory> <memory_resource> (C++17) <scoped_allocator> (C++11) 元编程 <meta> (C++26) <ratio> (C++11) <type_traits> (C++11)

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)

算法 <algorithm> <numeric> 字符串 <cctype> <cstring> <cuchar> (C++11) <cwchar> <cwctype> <string_view> (C++17) <string> 文本处理 <clocale> <codecvt> (C++11/17/26*) <locale> <regex> (C++11) <text_encoding> (C++26)    cpp/header#数值库数值 <cfenv> (C++11) <cmath> <complex> <linalg> (C++26) <numbers> (C++20) <random> (C++11) <simd> (C++26) <stdckdint.h> (C++26) <valarray> 时间 <chrono> (C++11) <ctime> C 兼容性 <ccomplex> (C++11/17/20*) <ciso646> (C++20 前) <cstdalign> (C++11/17/20*) <cstdbool> (C++11/17/20*) <ctgmath> (C++11/17/20*)

输入/输出 <cinttypes> (C++11) <cstdio> <filesystem> (C++17) <fstream> <iomanip> <iosfwd> <iostream> <ios> <istream> <ostream> <print> (C++23) <spanstream> (C++23) <sstream> <streambuf> <strstream> (C++98/26*) <syncstream> (C++20) 并发支持 <atomic> (C++11) <barrier> (C++20) <condition_variable> (C++11) <future> (C++11) <hazard_pointer> (C++26) <latch> (C++20) <mutex> (C++11) <rcu> (C++26) <semaphore> (C++20) <shared_mutex> (C++14) <stdatomic.h> (C++23) <stop_token> (C++20) <thread> (C++11) 执行支持 <execution> (C++17)

 

实验性库头文件

执行 P2300
<experimental/execution>
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