Type of result: const or not

[Wei Qin <wqin@xxxxxxxxxxxxxxxx>]

Hello,

	Scott Meyers recommends in his "50 specific ways ..." book that a
const typed object be returned from an operator. For instance,

const obj operator + (const obj& A, const obj& B);

	By doing so, things like below would be banned by the type-checker.
(a+b) = c;

	However, the stl with g++ does not return a const type, at least
in the complex and string cases. My questions is: which style is the
better one to follow?

thanks,

Wei