Operator< and strict weak ordering

Question

How to define operator< on n-tuple (for example on 3-tuple) so that it satisfy strict weak ordering concept ? I know that boost library has

Answer 1

Even if you can't use the boost version, you should be able to nick the code. I nicked this from std::pair - a 3 tuple will be similar I guess.

return (_Left.first < _Right.first ||
        !(_Right.first < _Left.first) && _Left.second < _Right.second);

Edit: As a couple of people have pointed out, if you steal code from the standard library to use in your code, you should rename things that have underscores on the front as these names are reserved.