Thomas Heller-7 wrote:
On Sat, May 14, 2011 at 8:18 PM, Vicente BOTET <vicente.botet@wanadoo.fr> wrote:
Hi,
I'm adding a convert_to Phoenix like functor to Boost.Conversion.
I would like to use the same name, i.e. convert_to, but the overloads conflict. I would like to use sfinae to choose the correct overloading between
template inline typename expression::convert_to, U>::type const convert_to(U const& u);
template Target convert_to(Source const& from, boost::dummy::base_tag const& p=boost::dummy::base_tag())
Is there a trait that can be used to detect if the parameter is a Phoenix expression?
There is boost::phoenix::is_actor<T>.
I will try it.
BTW, I have just based my implementation on the one for static_cast, that uses the detail boost::phoenix::detail::target
Could someone explain me why this is needed?
This is a dummy type just holding the type information to what the expressions needs to be casted to. It's also used in construct and new_. It's use is that the target type gets "decoded" in the expression tree without the target being default instantiated. (Some target types don't have default construction).
Oh, I see. Thanks for the explanation.
Could this detail be moved to the user interface? It's really just a implementation detail ... I don't know.
Doesn't matter. It seems it plays the same role that the template classes dummy::base_tag/type_tag I included in Boost.Conversion to transport the Target type. I will use my dummy classes instead. Thanks, Vicente -- View this message in context: http://boost.2283326.n4.nabble.com/Phoenix-is-there-a-Phoenix-expression-tra... Sent from the Boost - Dev mailing list archive at Nabble.com.