[Boost-users] Converting loop to using boost::lambda where containers has boost::shared_ptrs

From: Stephen Torri (storri_at_[hidden])
Date: 2007-05-18 21:00:46

I have a loop which I am trying to convert to using a boost::lambda
function.

        typedef std::vector< boost::shared_ptr<Verification_Type_Info> >
Append_Data_t;
        Append_Data_t m_data;

        ... Used in ....

        boost::uint32_t new_indent_limit = 2;

        for ( Append_Data_t::const_iterator cpos = m_data.begin();
              cpos != m_data.end();
              ++cpos )
            {
                output << (*cpos)->to_String ( new_indent_limit );
            }

Now I figure out that I can use the std::for_each algorithm for the
iteration. I just need to supply the beginning and end forward iterators
for m_data. What has me confused, since the lambda example page is not
clear to me, is how do I call the member function 'to_String' for each
Vertification_Type_Info object in the m_data container?

My idea was to do:

    std::for_each ( m_data.begin(),
                    m_data.end(),
                output << (_1 ->* &Verification_Type_Info::to_String) ( new_indent_limit ) );

This idea does not compile. I get errors about trying to send a
boost::lambda::operator->* to std::stringstream variable 'output'. If a
&_1 will give me the address of the object in the container at a
position will *_1 dereference the pointer at that position?

Stephen