Generics

• trivial syntactic cleanup: T extends string -> T: string

• stay the same basically

• in, out, in out, measured variance

• monomorph or not to monomorph

• how far? do we monomorph refs?

• JVM / CLR -> Go -> Rust / C++

• build vs release mode

• where clauses

• where clauses on members and extensions

• where clauses accept interface bounds, associated member bounds, and static equality constraints

any (trivially) statically decidable predicate

• foo<const T: isize>() where T > 5

• measured cardinality (like measured variance)

• generalised const parameter for value generics (literal types with a fixed cardinality of one, measured by usage like with variance)

• mutable arrays are invariant, readonly array views are covariant, and explicit copies may widen element values

• managed values follow derived variance under aliasing; owned and readonly storage may be covariant; mutable borrows, exclusive borrows, and raw pointers are exact

1function identity<T>(value: T): T {2    value3}

• obviously infer x and template inference and all that still works
• also partial generics / partial application
• explicit _ holes and inference
• like Array<_>
• or ^_
• or ``

Constraints

1function collect<T, C>(values: T[]): C where C: FromIterator<T> {2    values.intoIterator().collect()3}