Re: [Boost-users] how to make fusion::pair less-than-comparable?

Zeljko Vrba wrote:

Related to my previous question: fusion::map is a sequence and instances of it could be directly compared with operator < , thus vectors of instances also sorted if fusion::pair supported relational operators other than == and != (which it doesn't).

So, two questions:

1. What is the recommended way of defining operator< for particular pair instances (e.g. for pair) ?

2. An explanation of why doesn't fusion::pair define at least operator< would be welcome.

The reason is I don't know (yet) how to do 1 :-) If there are some suggestions, I see no reason why it can't be added to the library. So... how do you compare a half-static-half-runtime pair? Compare just the value part? How about pairs with different static parts but comparable runtime parts, how do they compare? Simply disallow? Comments, suggestions welcome. Regards, -- Joel de Guzman http://www.boostpro.com http://spirit.sf.net