This implements decision #565 to use `T:! Type` to declare generic parameters, and `template T:! Type` for template parameters.
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
To talk about generics as a programming language feature, you need a lot of
specialized terminology. We need to agree on the words we are using and their
meaning before we can meaningfully talk about the design of the feature itself.
There a number of problems a glossary solves:
Not everyone knows every term, so having a single place to look them up will
improve the ease of understanding, ease of contributing, and accessibility
of the project.
There may not be widespread agreement on the meaning of some terms. In
particular, individual programming languages tend to assign very specific
meanings to terms used within their ecosystem.
Some terms may be used in multiple ways, but we only use the term with one
specific meaning.
Some terms are our invention and we need to introduce them.
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
The "generics" feature of Carbon is a large design effort that needs to be broken up into manageable steps. The first thing we need is a high-level goals document. The goals here reflect the desirable properties that we have discovered as part of considering several alternative generics designs:
- Use cases:
- Generic programming
- Upgrade path from C++ abstract interfaces
- Dependency injection
- Generics instead of open overloading and ADL
- Performance
- Better compiler experience
- Encapsulation
- Predictability
- Dispatch control
- Upgrade path from templates
- Coherence
- No novel name lookup
- Learn from others
- Interfaces are nominal
- Interop and evolution
- Bridge for C++ customization points
Goals are summarized in [this presentation](https://docs.google.com/presentation/d/12yGyu5Pvdag7CJp-_yLVkmbhyvuRIilBTNlkO0LKaHo/edit?usp=sharing&resourcekey=0-JB9yrUO4-6J8-zzGhnIyNg).
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Co-authored-by: Jon Meow <46229924+jonmeow@users.noreply.github.com>
Co-authored-by: Matthew Riley <mdriley@gmail.com>
Co-authored-by: austern <austern@google.com>
Co-authored-by: Dmitri Gribenko <gribozavr@gmail.com>
josh11bandRichard Smith
Jeremy G. Siek
