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std::copyable_function:: operator bool

From cppreference.net
Utilities library
Function objects
Function invocation
(C++17) (C++23)
Identity function object
(C++20)
Old binders and adaptors
( until C++17* )
( until C++17* )
( until C++17* )
( until C++17* )
( until C++17* ) ( until C++17* ) ( until C++17* ) ( until C++17* )
( until C++20* )
( until C++20* )
( until C++17* ) ( until C++17* )
( until C++17* ) ( until C++17* )

( until C++17* )
( until C++17* ) ( until C++17* ) ( until C++17* ) ( until C++17* )
( until C++20* )
( until C++20* )
explicit operator bool ( ) const noexcept ;
(自 C++26 起)

检查 * this 是否存储了可调用目标,即非空状态。

目录

参数

(无)

返回值

* this 存储了可调用目标则为 true ,否则为 false

示例

参见

(C++26)
比较 std::copyable_function nullptr
(函数)
检查是否包含目标
( std::function<R(Args...)> 的公开成员函数)
检查 std::move_only_function 是否包含目标
( std::move_only_function 的公开成员函数)