Re: [Boost-users] [lambda & range] bind for transformed - how to do it.

29 Nov 2011


      On Tue, Nov 29, 2011 at 1:30 PM, Daniel James  wrote:
...
On 29 November 2011 13:09, Robert Jones  wrote:
...
In this code (fabricated) sequence, ages_by_bind compiles, but
ages_by_lambda
does not.
I believe this is because the lambda version does not publish
result_type to
its
resultant functors, since the increased generality of lambda makes this
difficult
or impossible to do.
Is there any way I can get round this, as it currently makes the
lambda/transformed
combination completely unusable AFAICS.
Have you tried using Phoenix? It has better support for result_type.
I have now, precisely because I'd understood it had better support as you
said. Like this,
perhaps someone could tell me if this is fine on 1.44/1.47 too!

Thx,

- Rob.

#include 
#include 
#include 

std::vector<int> ages_by_phoenix( const std::map & people
)
{
    namespace ph = boost::phoenix;
    namespace arg = boost::phoenix::arg_names;
    using boost::adaptors::transformed;

    std::vector<int> result;

    boost::range::push_back( result, people | transformed( ph::bind( &
std::map::value_type::second, arg::_1 ) ) );

    return result;
}