case-studies VS rust-blog

Luckily there is a workaround to emulate such a definition, which dtolnay discovered and explained here: https://github.com/dtolnay/case-studies/tree/b9802f6df8dc8e54970b83fb9af6df923b46abf5/unit-type-parameters.

I think they are talking about this one trick which the devs don't want you to know about. Note that while it looks like specialization, it works only in a few very limited cases and is quite fragile, so it's a hack, not a substitute for the real feature.

Also I suggest his case studies repo since you are looking at what is possible: https://github.com/dtolnay/case-studies

/u/dtolnay has a great case studies repository.

Once you have the basics down, read dtolnay's case studies. They show how to do advanced stuff with easy macros.

If you were writing your own println macro, you might be able to get away with this kind of hack: https://github.com/dtolnay/case-studies/blob/master/autoref-specialization/README.md

You can use "Autoref-based stable specialization" or use/mimic the impls crate.

With a subset of specialization likely riding the trains soon and a workaround available, why would you give up?

this works since values and types are in different namespaces (see: Rusts Universes or dtolnay's Case Study about "Unit struct with type parameters")

To do this with traits you would need specialization but since you are using macros you should be able to use "Autoref-based stable specialization". Here is a playground which uses the latter approach to implement the wanted macro without using any nightly features.

Hands down the best resource (after you've had sufficient experience with Rust, especially so) - https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md

I really really recommend reading this to understand lifetimes and generics in Rust better.

It's already now that the elided lifetimes are not always correct, as pointed out in Common Rust Lifetime Misconceptions (No 5) by pretzelhammer.

Common Rust Lifetime Misconceptions - kirill

Probably a bit more advanced than what you asked about, but still possibly useful: Common Rust Lifetime Misconceptions by /u/pretzelhammer.

This helped me a lot understanding Rust ownership rules and lifetimes: https://github.com/pretzelhammer/rust-blog/blob/master/posts/common-rust-lifetime-misconceptions.md