[Bug c++/53498] New: Compiler crashes during C++11 template magic compilation

[o.mangold at googlemail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53498

             Bug #: 53498
           Summary: Compiler crashes during C++11 template magic
                    compilation
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: o.mang...@googlemail.com


I was trying to create some template magic to create a check for the existence
of a function with variable number of arguments in C++11. Honestly, I don't
know, if my code should compile through, as the problem happened when I was
trying to figure out how to make it work. I got a compiler crash (which I guess
shouldn't happen in any case). I cooked it down to the example below:

> g++ -std=c++11 Crash.cxx

g++: internal compiler error: Segmentation fault (program cc1plus)
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.7/README.Bugs> for instructions.
kiwi/SafePrintf$g++ -std=c++11 Crash.cxx 
g++: internal compiler error: Segmentation fault (program cc1plus)
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-4.7/README.Bugs> for instructions.
---

--- Crash.cxx ---
template<typename... ARGS>
class A
{
public:
  template<typename U>
  auto a(const U& u,const ARGS&... args,int) -> decltype(u.print(args...))

  {
  }
  template<typename U>
  int a(const U& u,const ARGS&... args,...)

  {
  }

};

template<typename... ARGS>
class B
{
public:
  template<typename U> static void
  b(const U& u,const ARGS&... args,
    decltype(A<ARGS...>::a(u,args...,0)) dummy)
  {
  }
};

int main() {

  B<int> dummy;

  return 0;
}