http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51194
--- Comment #4 from Dodji Seketeli <dodji at gcc dot gnu.org> 2011-11-18 19:18:46 UTC --- Here is a smaller reproducer: template<class U, class V> struct foo {}; template<class U, class V=char> struct P {}; template<template<class... U> class... TT> struct bar { template<class... Args> using mem = P<TT<Args...>...>; }; bar<foo>::mem<int, char> b;