Hi. I have some template code that needs slightly different behavior when it is instantiated with exact types like int or boost::rational rather than when it is instantiated with floating point types. The compile-time test depends on std::numeric_limits<T>::is_exact. I was surprised when this came back false for boost::rational until I found that std::numeric_limits::is_specialized is false. Shouldn't boost::rational specialize numeric_limits? I'm using boost 1.54.0 with clang: Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM 3.2svn) compiling for C++1.