std::negate
template< class T >
struct negate;
| | (until C++14) |
template< class T = void >
struct negate;
| | (since C++14) |
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 (class template specialization) |
| (since C++14) |
Member types Type | Definition |
result_type (deprecated in C++17) | T |
argument_type (deprecated in C++17) | T |
| (until C++20) |
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
(none).
Possible implementation
constexpr T operator()(const T &arg) const
{
return -arg;
} |