Hello all, I have a SFINAE question. The following correctly returns false for eq1<x>::value when x has no operator== template< typename T > struct eq1 { T a; T b; template< typename TX > static char check ( TX a, TX b, char(*)[sizeof (std::is_convertible<decltype(a == b), bool>) ]); template< typename TX > static long check ( ... ); static const bool value = sizeof(char) == sizeof check<T>(a, b, 0); }; However, the following implementation that uses bool{a == b} incorrectly returns true for eq2<x>::value even if x has no operator==... why? BTW, if I just use (a == b) instead of bool{a == b} then it works... template< typename T > struct eq2 { T a; T b; template< typename TX > static char check ( TX a, TX b, char(*)[sizeof bool{a == b} ]); template< typename TX > static long check ( ... ); static const bool value = sizeof(char) == sizeof check<T>(a, b, 0); }; A complete example is attached. I'm using clang++ 3.2 with -std=c++0x. Thanks, --Lorenzo