How to C++11 static_assert for type constraint? -

how can make static_assert specific type constraint?

currently want make template unsigned int type, not signed int type. or, integral type, or specific type names. static_assert(sizeof(int)) offers size based assertion, , don't know how perform checks.

i using clang libc++ in xcode 4.6.2. here's current compiler information on command-line.

apple llvm version 4.2 (clang-425.0.28) (based on llvm 3.2svn) target: x86_64-apple-darwin12.3.0 thread model: posix 

that's not static_assert for, can this:

template<typename t> struct type {   static_assert(std::is_same<t, unsigned int>::value, "bad t"); }; 

or, if want t unsigned integral type of sort (not unsigned int):

template<typename t> struct type {   static_assert(std::is_unsigned<t>::value, "bad t"); };