removing elements from vector<int> using <algorithm>

WANTED:

/* C++ Primer - 4/e
 *
 * Exercise: 9.26
 * STATEMENT
 * Using the following definition of ia, copy ia into a vector and
 into a list. Use the single iterator form of erase to remove the
 elements with odd values from your list * and the even values from your
 vector.
 
  int ia[] = { 0, 1, 1, 2, 3, 5, 8, 13, 21, 55, 89 };
 *
 */
 

WHAT I GET:

/home/arnuld/programming/c++ $ g++ -ansi -pedantic -Wall -Wextra
ex_09.26.cpp ex_09.26.cpp:

In function 'int main()': ex_09.26.cpp:43:
error: '_1' was not declared in this scope /home/arnuld/programming/c++ $

CODE:

#include <iostream>
#include <vector>
#include <list>
#include <algorithm>
#include <iterator>

int main()
{
  int ia[] = { 0, 1, 1, 2, 3, 5, 8, 13, 21, 55, 89 };
  const size_t ia_size = sizeof( ia ) / sizeof( *ia );

  /* I made this array behave like a container:
        "ia_begin" is the pointer to 1st element of ia
    "ia_end" is the pointer to one past the last element of ia
  */
  int *ia_begin = ia;
  int *ia_end = ia + ia_size;

  std::vector<int> ivec;
  std::list<int> ilist;

  /* copy elements from array to vector & list */
  std::copy( ia_begin, ia_end, std::back_inserter( ivec ) );
  std::copy( ia_begin, ia_end, std::back_inserter( ilist ) );

  std::remove_if( ivec.begin(),
          ivec.end(),
          _1 % 2 == 0 );
  
  /* print out the values */
  std::copy( ivec.begin(), ivec.end(),
             std::ostream_iterator<int> (std::cout, "\n" ) );
               
  return 0;
}

I am just trying to use Lambda from Std. Lib. Why it is the problem ?

-- arnuld
http://lispmachine.wordpress.com