Template's Template

#include <cstdio>#include <tuple>template< class, class > struct S {  S() { puts("primary"); }};template<  template< class... > class T, class...TArgs, template< class... > class U, class...UArgs>struct S< T< TArgs... >, U< UArgs... > > {  S() { puts("specialized"); }};int main(){  S< int, int >  p;                                       // "primary"  S< std::tuple< int, char >, std::tuple< float > >  s;   // "specialised"}

D:\programming\C++>g++ -std=c++11 webDemo1.cppD:\programming\C++>aprimaryspecialized