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std::negate(3) C++ Standard Libary std::negate(3)

NAME

std::negate - std::negate

Synopsis


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


Function object for performing negation. Effectively calls operator- on an instance
of type T.

Specializations


The standard library provides a specialization of std::negate when T
is not specified, which leaves the parameter types and return type to
be deduced.
(since C++14)
negate<void> function object implementing -x deducing parameter and
(C++14) return types
(class template specialization)

Member types


Type Definition
result_type (deprecated in C++17)(removed in C++20) T
argument_type (deprecated in C++17)(removed in C++20) T


These member types are obtained via publicly inheriting (until C++11)
std::unary_function<T, T>.

Member functions


operator() returns the negation of the argument
(public member function)

std::negate::operator()


T operator()( const T& arg ) const; (until C++14)
constexpr T operator()( const T& arg ) const; (since C++14)


Returns the negation of arg.

Parameters


arg - value to compute negation of

Return value


The result of -arg.

Exceptions


May throw implementation-defined exceptions.

Possible implementation


constexpr T operator()(const T& arg) const
{
return -arg;
}

2024.06.10 http://cppreference.com