Toon Knapen wrote:

...

Hope it's not too complicated :). LL might allow to do better on this one.

Thanks, I'll try it out. Coudl you enlighten me on how to solve it with the lambda library. I don't see how to iterate over the different indexes in combination with LL ?

Oh, sorry, my last sentence was probably misleading. What I meant is that LL can do a better job on construction of the function object that is passed to tuple's 'accumulate': struct get_value { template< typename T > int operator()(T const& x) const { return x.value(); } }; int sum = accumulate(tuple, 0, _1 + ll::bind(get_value(),_2)); I was also hoping that it could help us to get rid of the ad hoc 'get_value' class, but, thinking about it more, I don't see how :(. HTH, Aleksey