std::multiplies
From cppreference.com
                    
                                        
                    < cpp | utility | functional
                    
                                                            
                    | Defined in header  <functional> | ||
| template< class T > struct multiplies; | (until C++14) | |
| template< class T = void > struct multiplies; | (since C++14) | |
Function object for performing multiplication. Effectively calls operator* on two instances of type T.
Specializations
| The standard library provides a specialization of  
 | (since C++14) | 
Member types
| Type | Definition | 
| result_type(deprecated in C++17) | T | 
| first_argument_type(deprecated in C++17) | T | 
| second_argument_type(deprecated in C++17) | T | 
Member functions
| operator() | returns the product of two arguments (public member function) | 
std::multiplies::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 product of lhs and rhs.
Parameters
| lhs, rhs | - | values to multiply | 
Return value
The result of lhs * rhs.
Exceptions
(none)
Possible implementation
| constexpr T operator()(const T &lhs, const T &rhs) const { return lhs * rhs; } |