On Tuesday, 26 December 2017 at 19:41:47 UTC, rumbu wrote: > "Custom" is a templated struct. I cannot imagine all the > instantiations of Custom to write template specialisations for > each of them. You can specialize on templated structs generically. int foo(T : Bar!(X, Y), X, Y) that kind of thing covers any case of Bar!(X,y)