[Boost-users] variant comparison operators

From: Jiri Palecek (jpalecek_at_[hidden])
Date: 2008-03-28 11:54:05

Hello,

is there some deep reason why comparing variant to a nonvariant is  
disabled? For example:

variant<int, string> v=1;
assert(v==1); // doesn't compile

The problem is that there are overloads for anything else than a variant,  
which explicitely fail to compile (via static_assert and other means). If  
they weren't there, everything would work (the comparison would invoke  
conversion constructor, and then normal variant/variant comparison.

Another problem is that variant includes the == operator, but not !=, even  
though this could be easily achieved with boost::operators.

I can send patches if that would help.

Regards
     Jiri Palecek