Defined in header <functional>
template< class T > (until C++14)
struct plus;
template< class T = void > (since C++14)
struct plus;
Function object for performing addition. Effectively calls operator+ on two
instances of type T.
The standard library provides a specialization of std::plus when
T is
not specified, which leaves the parameter types and return type to be
deduced.
(since C++14)
plus<void> function object implementing x + y deducing argument and
(C++14) return types
(class template specialization)
Type Definition
result_type (deprecated in C++17)(removed in C++20) T
first_argument_type (deprecated in C++17)(removed in C++20) T
second_argument_type (deprecated in C++17)(removed in C++20) T
These member types are obtained via publicly inheriting (until C++11)
std::binary_function<T, T, T>.
operator() returns the sum of two arguments
(public member function)
std::plus::operator()
T operator()( const T& lhs, const T& rhs ) const; (until
C++14)
constexpr T operator()( const T& lhs, const T& rhs ) const; (since
C++14)
Returns the sum of lhs and rhs.
May throw implementation-defined exceptions.
constexpr T operator()(const T &lhs, const T &rhs) const
{
return lhs + rhs;
}