strongly typed enums in g++-4.4
c++, c++11, g++, strongly-typed-enum
Solution
It's a known bug. As @Casey found out, originally `g++-4.4` did not support any relational operations on strongly-typed enums. For equality, this was fixed in version `4.4.1`, but the fix for all other relations such as `<` and `>` only made it into `4.5.1` and above.
This is the original bug thread on the gcc bugzilla: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38064
Problem
According to the GCC C++11 support status website, strongly typed enums are available for `g++4.4` and greater. However the following does not compile with `g++4.4`: ``` enum class Foo { value_1, value_2 }; int main() { Foo a = Foo::value_1; Foo b = Foo::value_2; const bool test = ( a < b ); } ``` The error message is `error: invalid operands of types ‘Foo’ and ‘Foo’ to binary ‘operator<’`. Compilers that accept the code include `g++-4.6`, `g++-4.7`, `g++-4.8` and `clang++ 3.2`. ( I couldn't test with `g++-4.5` as I don't have it installed currently (and Ubuntu 13 doesn't want me to)) I could easily provide a fallback for this (rather old) compiler with a macro, but I generally dislike that (where does it stop?...). What's the problem here? Is the information of support wrong or is another bit missing that's not included in "support for strongly-typed enums"? Last option I can think of: Is the problem in my code?