id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
5190,boost::phoenix operator+ sometimes returns a reference to a temporary leading to undefined behaviour,nicos@…,Joel de Guzman,"Compiling:
{{{
const float x = 1.0f;
const float y = 1.0f;
std::cout << (arg1+arg2)(x,y);
}}}

with gcc results in the following warning:
/usr/local/boost_1_45_0/boost/spirit/home/phoenix/operator/arithmetic.hpp:74: warning: returning reference to temporary

The trouble is that result_of_plus<const float, const float>::type is const float& instead of float.
The source of the issue is that float is not supported ""natively"" by phoenix type deduction system ( if float is replaced by int, then the return type is correctly deduced ), the selected test overload is:
{{{
    template <typename X, typename Y>
    typename disable_if<
        is_basic<X>
      , x_reference_type
    >::type
    test(X&);
}}}

As a result a reference to a temporary is returned that leads to undefined behaviour in programs compiled with heavy optimizations (-O3).",Bugs,closed,To Be Determined,phoenix,Boost 1.45.0,Showstopper,fixed,,