Cannot mock methods with inputs that refer to unimock's lifetime

[audunhalland]

E.g. https://doc.rust-lang.org/std/io/trait.Read.html#method.read_vectored

[audunhalland]

In e.g.

    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) {

The lifetime inside the IoSliceMut must outlive the lifetime of bufs. They have to be two different lifetimes.

In order to encode this, MockFn could have type Inputs<'i0, 'i1: 'i0>;. But as soon as it has this, it becomes quite hard to express a HRTB that type checks.

The HRTB must introduce two lifetimes with an outlives-relation between them. This is not supported. See Extended HRTB RFC proposal

[audunhalland]

Experimental branch: https://github.com/audunhalland/unimock/tree/unimock-input-lifetime

But ran into the "HRTB must outlive" issue:
rust-lang/rust#100013