C++11 compiler error when using decltype(var) followed by internal type of “var”

Question

I\'m using Visual C++ 2010, and here\'s my code snippet:

std::set s;
decltype(s)::value_type param = 0;

I got the following erro

Answer 1

I see that with g++ 4.7.2 version, the code compiles fine. So it could be a compiler bug in MSVS.
For time being you can try below trick:

#ifdef COMPILER_BUG_STILL_THERE
template struct Get { typedef T type; };
#define DECLTYPE(VAR) Get::type
#else
#define DECLTYPE(VAR) decltype(VAR)
#endif

Use it as:

DECLTYPE(s)::value_type param = 0;

Disclaimer: Ofcourse with this trick, you may have to use typename when inside templates. For that you can have 1 more macro such as #define TDECLTYPE(VAR) typename DECLTYPE(VAR)