How can I cleanly specify which arguments I am passing and which remain default?

Question

Asked because of this: Default argument in c++

Say I have a function such as this: void f(int p1=1, int p2=2, int p3=3, int p4=4);

And

Answer 1

Use the Named Parameters Idiom (→ FAQ link).

The Boost.Parameters library (→ link) can also solve this task, but paid for by code verbosity and greatly reduced clarity. It's also deficient in handling constructors. And it requires having the Boost library installed, of course.