(WIP) rustc: Implement nested C-like enums #17050

pczarn · 2014-09-06T19:40:58Z

Allows #[repr(XX)] on more complex enums. Checks for inner variant collisions.

Example

// exception.rs
#[repr(u8)]
pub enum Fault {
    DivideError = 0,
    NMI = 2,
    Breakpoint = 3,
    // ...
}

// interrupt.rs
#[repr(u8)]    // < this is allowed
pub enum Interrupt {
    Fault(Fault),
    IRQ0 = 32,
    IRQ1 = 33,
    Syscall = 0x80
}

huonw · 2014-09-07T00:50:22Z

I wonder if this could be approached as a general enum-discriminant collapsing optimisation, with C-like enums + #[repr] a natural consequence?

E.g.

enum Foo {
    A, B, C
}
enum Bar {
     X(Foo), Y
}

enum Baz {
      S(Bar), T(int)
}

would "inline" the discriminant values of their sub-enum.

brson · 2014-09-09T23:33:28Z

This seems pretty RFC-worthy to me. I've never heard any suggestion that we extend C-like enums in this way.

alexcrichton · 2014-09-17T15:42:40Z

I agree with @brson that this looks like it needs an RFC to move forward as it's a bit of a language change. Closing.

…r=Veykril internal: make function builder create ast directly I am working on rust-lang#17050. In the process, I noticed a place in the code that could be refactored. Currently, the `function builder` creates the `ast` through the `function template` , but those two processes can be combined into one function. I thought I should work on this first and created a PR.

…-new, r=Veykril feature: Make generate function assist generate a function as a constructor if the generated function has the name "new" and is an asscociated function. close rust-lang#17050 This PR makes `generate function assist` generate a function as a constructor if the generated function has the name "new" and is an asscociated function. If the asscociate type is a record struct, it generates the constructor like this. ```rust impl Foo { fn new() -> Self { Self { field_1: todo!(), field_2: todo!() } } } ``` If the asscociate type is a tuple struct, it generates the constructor like this. ```rust impl Foo { fn new() -> Self { Self(todo!(), todo!()) } } ``` If the asscociate type is a unit struct, it generates the constructor like this. ```rust impl Foo { fn new() -> Self { Self } } ``` If the asscociate type is another adt, it generates the constructor like this. ```rust impl Foo { fn new() -> Self { todo!() } } ```

pczarn added 2 commits September 6, 2014 20:07

rustc: Implement nested C-like enums

8b03c25

cleanup

6743ba0

pczarn changed the title ~~rustc: Implement nested C-like enums~~ (WIP) rustc: Implement nested C-like enums Sep 6, 2014

alexcrichton closed this Sep 17, 2014

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(WIP) rustc: Implement nested C-like enums #17050

(WIP) rustc: Implement nested C-like enums #17050

pczarn commented Sep 6, 2014

huonw commented Sep 7, 2014

brson commented Sep 9, 2014

alexcrichton commented Sep 17, 2014

(WIP) rustc: Implement nested C-like enums #17050

(WIP) rustc: Implement nested C-like enums #17050

Conversation

pczarn commented Sep 6, 2014

Example

huonw commented Sep 7, 2014

brson commented Sep 9, 2014

alexcrichton commented Sep 17, 2014