std::multiplies<void>

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< cpp‎ | utility‎ | functional
 
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Defined in header <functional>
template<>
class multiplies<void>;
 (since 哋它亢++14)

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

Nested types

Nested type Definition
is_transparent unspecified

Member functions

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

std::multiplies<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 product of lhs and rhs.

Parameters

lhs, rhs - values to multiply

Return value

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

Example

Run this code
#include <complex>
#include <functional>
#include <iostream>
 
int main()
{
    auto complex_multiplies = std::multiplies<void>{}; // “void” can be omitted
    constexpr std::complex z1{1.0, 2.0}, z2{3.0, 4.0};
 
    std::cout << std::showpos
              << complex_multiplies(z1, z2) << ' ' << z1 * z2 << '\n'
              << complex_multiplies(z1, 5.) << ' ' << z1 * 5. << '\n'
              << complex_multiplies(5., z1) << ' ' << 5. * z1 << '\n';
}

Output: 

(-5,+10) (-5,+10)
(+5,+10) (+5,+10)
(+5,+10) (+5,+10)
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