Unbaked Idea: DRY using "parameterized inline modules"

[Ixrec]

@elidupree

The automatic merging of the parameter lists also seems confusing. If you just looked at the type signature of foo where it appeared in the file, you’d write the wrong number of generic parameters and then be confused that the compiler was giving you errors for not giving enough generic parameters. (Good error messages could alleviate this a bit, but it still seems counterintuitive.) In particular, you could easily have a fn foo that USES a type parameter from the PIM, but only in its body, and doesn’t refer to that type in its signature, so there isn’t even a hint that you need to go look for the definition of that type. At first glance, I’d prefer having the 2 lists be separate, like the C++ way where you say scope<parameters>::specific_struct<parameters> . That seems pretty similar to a having explicit, named, parameterized modules.

As long as we're spitballing syntaxes, here's a random thought: we could use an explicit ...

mod<A, B, C> {
    fn foo<..>() -> B { ... }
    fn bar<.., X>() -> X { ... }
}