id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
2246,Phoenix2 lazy function compilation error,François Barel <frabar666@…>,Joel de Guzman,"I get a compilation error when trying to do a lazy Phoenix function.

By that I mean a Phoenix function (for use in a Spirit action) which is in fact the result of calling another Phoenix actor (in my case a phoenix::bind) -- as the implementation of {{{function}}}, {{{compose}}} and {{{function_eval}}} seems to allow (IIUC the function can be any Phoenix actor, just like its arguments).

[[BR]]

Repro:

{{{
#include <boost/spirit/include/qi.hpp>
using namespace ::boost::spirit;
using namespace ::boost::spirit::qi;

#include <boost/spirit/include/phoenix_bind.hpp>
#include <boost/spirit/include/phoenix_function.hpp>
#include <boost/spirit/include/phoenix_operator.hpp>
using namespace ::boost::phoenix;

template< typename F >
function< F > make_function(const F& f)
    { return function< F >(f); }

struct Actor
{
    typedef void result_type;
    template< typename T = unused_type >
    struct result { typedef result_type type; };
    void operator()(int) const { assert( this != NULL ); }
};

struct Context
{
    const Actor* pa;
};

int main()
{
    Context c = { NULL };
    Actor a;

    rule< const wchar_t* > r;
    // Not lazy, fine.
    r = eps[ make_function( a                        )(42) ];
    // Lazy, compilation error.
    r = eps[ make_function( *bind( &Context::pa, c ) )(42) ];

    c.pa = &a;

    const wchar_t* x = L"""";
    parse(x, x, r);

    return 0;
}
}}}

The error is (note the '{{{&}}}'):

{{{
boost/spirit/home/phoenix/core/detail/function_eval.hpp:108:
  error: ‘const Actor&’ is not a class, struct, or union type
}}}

[[BR]]

The attached patch ({{{remove_reference}}} when getting function type) solved it for me.

Francois
",Bugs,closed,Boost 1.37.0,spirit,Boost 1.36.0,Problem,fixed,phoenix lazy function,