https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66153
--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Reduced further:
#include <type_traits>
template <class T> struct TypeMapper { static const int NestLevel =
T::NestLevel; };
template<> struct TypeMapper<double> { static const int NestLevel = 0; };
template<class obj> struct Container { obj data; };
template<class obj> struct Recursive {
enum { NestLevel = TypeMapper<obj>::NestLevel + 1};
};
template<int N,class obj, typename std::enable_if<N==obj::NestLevel >::type *
= nullptr >
auto function(const obj &arg)-> obj
{
return arg;
}
template<int N,class obj, typename std::enable_if<N!=obj::NestLevel >::type * =
nullptr >
auto function(const obj &arg)-> obj
{
return obj{};
}
template<int N,class obj>
auto function(const Container<obj> & arg) ->
Container<decltype(function<N>(arg.data))>
{
Container<Recursive<Recursive<double> > > ret;
return ret;
}
int main(int argc,char **argv)
{
Container<Recursive<Recursive<double> > > array;
Container<Recursive<Recursive<double> > > ret;
function<1>(array);
}
----- CUT -----
I have seen another one similar to this recently.
