[Proto] Detecting if a tag is a proto type or not
I want to do some dispatching based on the fatc that my binary_expr tag is one of predefined proto tag or not. What kind of internal properties of proto tags can I try to use to perform this discrimination ? Thanks in advance
Joel Falcou wrote:
I want to do some dispatching based on the fatc that my binary_expr tag is one of predefined proto tag or not. What kind of internal properties of proto tags can I try to use to perform this discrimination ?
Well, they're defined in the boost::proto::tag namespace. You can play tricks with ADL and sizeof.... -- Eric Niebler BoostPro Computing http://www.boostpro.com
Joel Falcou wrote:
Eric Niebler a écrit :
Well, they're defined in the boost::proto::tag namespace. You can play tricks with ADL and sizeof....
Care to elaborate a few ?
Something like this:
namespace boost { namespace proto { namespace tag {
template<typename T>
char check_is_proto_tag(T);
}}}
namespace not_proto
{
char (&check_is_proto_tag(...))[2];
}
using not_proto::check_is_proto_tag;
template<typename T>
struct is_proto_tag
: boost::mpl::bool_
participants (2)
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Eric Niebler -
Joel Falcou