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std::minus<void>

From cppreference.com
< cpp‎ | utility‎ | functional
 
 
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(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*)
 
Defined in header <functional>
template<>
class minus<void>;
(since C++14)

std::minus<void> is a specialization of std::minus with parameter and return type deduced.

Contents

[edit] Member types

Type Definition
is_transparent unspecified

[edit] Member functions

operator()
returns the difference of two arguments
(public member function)

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

template< class T, class U >

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

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

Returns the difference of lhs and rhs.

Parameters

lhs, rhs - values to subtract

Return value

std::forward<T>(lhs) - std::forward<U>(rhs).

[edit] Example

#include <complex>
#include <functional>
#include <iostream>
 
int main()
{
    auto complex_minus = std::minus<void>{}; // “void” can be omitted
    constexpr std::complex<int> z(4, 2);
    std::cout << complex_minus(z, 1) << '\n';
    std::cout << (z - 1) << '\n';
}

Output:

(3,2)
(3,2)