list::remove_if

Erases elements from a list for which a specified predicate is satisfied.

template<class Predicate> 
void remove_if(
   Predicate _Pred
)

Parameters

  • _Pred
    The unary predicate which, if satisfied by an element, results in the deletion of that element from the list.

Example

// list_remove_if.cpp
// compile with: /EHsc
#include <list>
#include <iostream>

template <class T> class is_odd : public std::unary_function<T, bool> 
{
public:
   bool operator( ) ( T& val ) 
   {
   return ( val % 2 ) == 1;
   }
};

int main( ) 
{
   using namespace std;
   list <int> c1;
   list <int>::iterator c1_Iter, c2_Iter;
   
   c1.push_back( 3 );
   c1.push_back( 4 );
   c1.push_back( 5 );
   c1.push_back( 6 );
   c1.push_back( 7 );
   c1.push_back( 8 );

   cout << "The initial list is c1 =";
   for ( c1_Iter = c1.begin( ); c1_Iter != c1.end( ); c1_Iter++ )
      cout << " " << *c1_Iter;
   cout << endl;
   
   list <int> c2 = c1;
   c2.remove_if( is_odd<int>( ) );

   cout << "After removing the odd elements, "
        << "the list becomes c2 =";
   for ( c2_Iter = c2.begin( ); c2_Iter != c2.end( ); c2_Iter++ )
      cout << " " << *c2_Iter;
   cout << endl;
}

The initial list is c1 = 3 4 5 6 7 8
After removing the odd elements, the list becomes c2 = 4 6 8

Requirements

Header: <list>

Namespace: std

See Also

Concepts

list Class

list Class Members

Standard Template Library