std::negate<void>

 

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Operator wrappers plus minus negate multiplies divides modulus bit_and bit_or bit_not (C++14)   bit_xor equal_to not_equal_to greater less greater_equal less_equal logical_and logical_or logical_not	Transparent operator wrappers plus<> (C++14) minus<> (C++14) negate<> (C++14) multiplies<> (C++14)   divides<> (C++14) modulus<> (C++14) bit_and<> (C++14) bit_or<> (C++14) bit_not<> (C++14) bit_xor<> (C++14) equal_to<> (C++14) not_equal_to<> (C++14) greater<> (C++14) less<> (C++14) greater_equal<> (C++14) less_equal<> (C++14) logical_and<> (C++14) logical_or<> (C++14) logical_not<> (C++14)
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unary_function (until C++17*) binary_function (until C++17*) ptr_fun (until C++17*) pointer_to_unary_function (until C++17*) pointer_to_binary_function (until C++17*)   mem_fun (until C++17*) mem_fun_tmem_fun1_tconst_mem_fun_tconst_mem_fun1_t (until C++17*)(until C++17*)(until C++17*)(until C++17*) not1 (until C++20*) not2 (until C++20*)	binder1stbinder2nd (until C++17*)(until C++17*) bind1stbind2nd (until C++17*)(until C++17*) mem_fun_ref (until C++17*) mem_fun_ref_tmem_fun1_ref_tconst_mem_fun_ref_tconst_mem_fun1_ref_t (until C++17*)(until C++17*)(until C++17*)(until C++17*) unary_negate (until C++20*) binary_negate (until C++20*)

 

Defined in header <functional>
template<> class negate<void>;		(since C++14)

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

Member types

Type	Definition
is_transparent	unspecified

Member functions

operator()

returns its negated argument (public member function)

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

template<class T > constexprauto operator()( T&& arg )const     -> decltype(-std::forward<T>(arg));

Returns the result of negating arg.

Parameters

arg

-

value to negate

Return value

-std::forward<T>(arg).

Example

Run this code

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

Output:

(4,2) (-4,-2) (-4,-2)