plus Struct

The struct provides a predefined function object that performs the arithmetic operation of addition on elements of a specified value type.

template<class Type> 
   struct plus : public binary_function <Type, Type, Type>  
   { 
      Type operator()( 
         const Type& _Left,  
         const Type& _Right 
      ) const; 
   };

Parameters

• _Left
  A number that is of the parameter type Type that is to be added by the function object.

• _Right
  A number that is of the parameter type Type that is to be added by the function object.

Return Value

The sum _Left + _Right.

Example

// functional_plus.cpp
// compile with: /EHsc
#include <vector>
#include <functional>
#include <algorithm>
#include <iostream>

using namespace std;

int main( )
{
   vector <double> v1, v2, v3 ( 6 );
   vector <double>::iterator Iter1, Iter2, Iter3;
   
   int i;
   for ( i = 0 ; i <= 5 ; i++ )
      v1.push_back( 4 * i );

   int j;
   for ( j = 0 ; j <= 5 ; j++ )
      v2.push_back( -2.0 * j - 4 );

   cout << "The vector v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;

   cout << "The vector v2 = ( " ;
   for ( Iter2 = v2.begin( ) ; Iter2 != v2.end( ) ; Iter2++ )
      cout << *Iter2 << " ";
   cout << ")" << endl;

   // Finding the element-wise sums of the elements of v1 & v2
   transform (v1.begin( ), v1.end( ), v2.begin( ), v3.begin ( ), plus<double>( ) );

   cout << "The element-wise sums are: ( " ;
   for ( Iter3 = v3.begin( ) ; Iter3 != v3.end( ) ; Iter3++ )
      cout << *Iter3 << " ";
   cout << ")" << endl;
}

The vector v1 = ( 0 4 8 12 16 20 )
The vector v2 = ( -4 -6 -8 -10 -12 -14 )
The element-wise sums are: ( -4 -2 0 2 4 6 )

Requirements

Header: <functional>

Namespace: std

See Also

Reference

Thread Safety in the Standard C++ Library

Standard Template Library