move semantics

[andrewrk]

Let's say we have a non-copyable List data structure (current implementation in std matches this because of the prealloc_data field).

// non-copyable
struct List { ... }

struct Buffer {
    data: List(u8),
}

struct Token {
    name: Buffer,
}

struct CompletedTokenization {
    tokens: List(Token),
}

List(Token) is (not currently but should be) a compile error because the list implementation calls realloc on T which copies the data. And List itself is non-copyable, so that bubbles up and means you can't have tokens: List(Token).

1. Make this a compile error.
2. Should we specify move semantics so that this can actually be allowed and work correctly?

[pavildon]

may be not related but: any plans to make object lifetimes accesible in some way to templates so they can be compared at compile time? (ie, if an object can outlive me ('a<'b) i can not share a resource) (ala A' / B' on rust) IMO if this feature is implemented should be optional. as introduces too much noise in the templates definitions

[andrewrk]

Closing in favor of #287