On Tue, Mar 23, 2010 at 4:29 AM, Robert Jones wrote:

Hi All

Ok, now I've found out what is really stopping my real code working.

In this example my problem is that method has defaulted arguements, which I think mucks up bind's signature matching. Is there an easy way round this, or must I just add appropriate overloads of double_it to A?

Thanks, Rob.

#include <algorithm> #include <vector> #include "boost/bind.hpp"

struct A {     int double_it( int i, int j = 2 ) { return i * j; } } a;

std::vector< int > v;

int main( ) {     for ( std::vector< int >::iterator i = v.begin( ); i != v.end( ); ++ i )     {         a.double_it( * i );     }

    // Write it as a for_each/bind     std::for_each( v.begin(), v.end(), boost::bind( & A::double_it, boost::ref( a ), _1 ) ); }

C++ type signatures do not see optional parameters, thus, pretend that your function does not have a default value: #include <algorithm> #include <vector> #include "boost/bind.hpp" struct A { int double_it( int i, int j = 2 ) { return i * j; } } a; std::vector< int > v; int main( ) { for ( std::vector< int >::iterator i = v.begin( ); i != v.end( ); ++ i ) { a.double_it( * i ); } // Write it as a for_each/bind std::for_each( v.begin(), v.end(), boost::bind( & A::double_it, boost::ref( a ), _1, 2 ) ); }