Steven Watanabe wrote:
Eric Niebler wrote:
One of the big sources of slow-down is the operator() overloads on expr<> ... there are N specializations of expr<>, and each one has N overloads of operator(). That's O(N^2) growth. With a variadic operator(), I should be able to knock that down to O(N).
In that case, since Marcus wants a larger arity for automatically generated exprs rather than ones created using operators, couldn't you set the max arity for the function call overloads separately from the max expr arity? How are compile times if you keep the function call arity fixed at 5?
A quick test shows this to be a very good way to keep compile times under control. Max arity Max Function call arity Compile time (sec) ------------------------------------------------------------------ 40 40 24.1 40 5 14.0 Thanks for the suggestion. -- Eric Niebler Boost Consulting www.boost-consulting.com