On Mar 10, 2004, at 2:10 PM, Neal D. Becker wrote:

I was just trying out lambda and I have a question.

I have a template class Ave template<typename in_t, typename Scale> struct Ave {...}

It takes a function type argument "Scale".

Here's a test:

typedef typeof (_1 * 0.1) some_type; some_type func (_1 * 0.1);

// Ave<double, typeof (_1 * 0.1)> ave (_1 * 0.1); << this will work Ave<double, some_type> ave (func); << this will also

What is the preferred way to do this without "typeof"? How do I get the type returned by the lambda expression to feed to the template Ave?

There is no direct way of getting to the type. One can store a lambda expression into a boost::function, for which you have to specify the return and argument types: boost::function<double (double)> func = _1 * 0.1; Cheers, Jaakko