bind2nd doesnt accept methods using pass-by-ref?

[Rob Willis]

Still learning the ins and outs of STL.  I hit the following case, where
bind2nd can not take accept methods that use pass-by-reference.  That
seems very limiting...  I looked in the bind2nd definition, it appears
as if the bind2nd template is saving a copy of the value to be passed
into the method - is this what the standard requires??  Seems like in
many cases you would want the bind2nd to just save a ref to the value...

-Rob

rob@e-critical.com


#include <functional>
#include <algorithm>
#include <vector>

using namespace std;

class Base
{
public:

virtual void testOp1( const double * d_ptr ) = 0;

virtual void testOp2( const double & d_ref ) = 0;
};

int main()
{
std::vector< Base * > vObjects;
double  d_value = 1.0;

// this compiles
for_each( vObjects.begin(), vObjects.end(),
bind2nd( mem_fun( &Base::testOp1 ), &d_value ) );

/* // this doesnt compile
for_each( vObjects.begin(), vObjects.end(),
bind2nd( mem_fun( &Base::testOp2 ), d_value ) );
*/
}