This can already be done using Linq in C++, which is range-based rather than iterator based: auto q = LINQ( from(z, boost::irange(1, std::n

This can already be done using Linq in C++, which is range-based rather than iterator based: auto q = LINQ( from(z, boost::irange(1, std::numerical_limits<int>::max())) from(x, boost::irange(1, z)) from(y, boost::irange(1, x)) where(x*x + y*y == z*z) select(boost::fusion::make_vector(x, y, z)) ); for(auto&& x:q | linq::take(10)) std::cout << x << std::endl; Hopefully, once we get ranges in the C++ standard library, we can add list comprehension to the language, perhaps something like this: auto q = [ for (z, std::irange(1, std::numerical_limits<int>::max())) for (x, std::irange(1, z)) for (y, std::irange(1, x)) if (x*x + y*y == z*z) boost::fusion::make_vector(x, y, z) ]; for(auto&& x:q | std::take(10)) std::cout << x << std::endl;