std::negate (3) - Linux Manuals

std::negate: std::negate

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.

             function object implementing -x deducing argument and return types (since C++14)
negate<void> (class template specialization)

Member types

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

Member functions

           returns the negation of the argument
operator() (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

(none)

Possible implementation

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