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std:: equal_to<void>

From cppreference.net
C++
Utilities library
Function objects
Function invocation
(C++17) (C++23)
Identity function object
(C++20)
Old binders and adaptors
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定义于头文件 <functional>
template <>
class equal_to < void > ;
(C++14 起)

std:: equal_to < void > 是 std::equal_to 的特化版本，其参数和返回类型由编译器自动推导。

目录

嵌套类型

嵌套类型 定义
is_transparent 未指定

成员函数

operator()
测试两个参数是否比较相等
(公开成员函数)

std::equal_to<void>:: operator()

template < class T, class U >

constexpr auto operator ( ) ( T && lhs, U && rhs ) const

- > decltype ( std:: forward < T > ( lhs ) == std:: forward < U > ( rhs ) ) ;

返回 lhs 与 rhs 的相等比较结果。

参数

lhs, rhs - 要比较的值

返回值

std:: forward < T > ( lhs ) == std:: forward < U > ( rhs ) 。

示例

运行此代码 
#include <functional>
int main()
{
    constexpr int a = 0, b = 8;
    std::equal_to<> equal{};
    static_assert(equal(a, a));
    static_assert(!equal(a, b));
}