Compiler errors (Copy constraint on Buffer)

[bvssvni]

The methods on Cell requires a Copy constraint, which is no longer implemented by Buffer.

src/chunk.rs:113:40: 113:45 error: type `&core::cell::Cell<core::option::Option<shader::Buffer>>` does not implement any method in scope named `get`
src/chunk.rs:113                 f(x, y as i32, z, c, b.get())
                                                        ^~~~~
src/chunk.rs:113:45: 113:45 help: methods from traits can only be called if the trait is implemented and in scope; the following traits define a method `get`, perhaps you need to implement one of them:
src/chunk.rs:113:45: 113:45 help: candidate #1: `core::slice::SliceExt`
src/chunk.rs:113:45: 113:45 help: candidate #2: `collections::slice::SliceExt`
src/chunk.rs:113:45: 113:45 help: candidate #3: `quack::get::Get`
src/minecraft/region.rs:143:41: 143:50 error: the trait `core::marker::Copy` is not implemented for the type `shader::Buffer` [E0277]
src/minecraft/region.rs:143             buffers: Array::from_fn(|_| Cell::new(None)),
                                                                    ^~~~~~~~~
src/main.rs:294:38: 294:43 error: type `&core::cell::Cell<core::option::Option<shader::Buffer>>` does not implement any method in scope named `get`
src/main.rs:294                         match buffer.get() {
                                                     ^~~~~
src/main.rs:294:43: 294:43 help: methods from traits can only be called if the trait is implemented and in scope; the following traits define a method `get`, perhaps you need to implement one of them:
src/main.rs:294:43: 294:43 help: candidate #1: `core::slice::SliceExt`
src/main.rs:294:43: 294:43 help: candidate #2: `collections::slice::SliceExt`
src/main.rs:294:43: 294:43 help: candidate #3: `quack::get::Get`
src/main.rs:302:32: 304:27 error: type `&core::cell::Cell<core::option::Option<shader::Buffer>>` does not implement any method in scope named `set`
src/main.rs:302                         buffer.set(Some(
src/main.rs:303                             renderer.create_buffer(staging_buffer.as_slice())
src/main.rs:304                         ));
src/main.rs:304:27: 304:27 help: methods from traits can only be called if the trait is implemented and in scope; the following trait defines a method `set`, perhaps you need to implement it:
src/main.rs:304:27: 304:27 help: candidate #1: `quack::set::Set`
error: aborting due to 4 previous errors
Could not compile `hematite`.

[bvssvni]

The PR that broke it in Gfx was gfx-rs/gfx#507

[bvssvni]

sectopod/gfx-rs@7de1690#diff-9727ac41ee298b338aa97b20cd10c264L204

[bvssvni]

No, I was wrong. The Copy constraint was moved here sectopod/gfx-rs@7de1690#diff-9727ac41ee298b338aa97b20cd10c264R214

[bvssvni]

The problem is that Copy is implemented with a where constraint.

I guess, somehow the <ShaderParam as gfx::shade::ShaderParam>::Link is not Copy.

[eddyb]

There should be a rust issue about deriving not working correctly with associated types.

[toqueteos]

Dup of #170 ?

[bvssvni]

@eddyb Are you suspicious about this being a bug in Rust?

[eddyb]

It's a known issue, and I expect there to an issue open on it in the Rust repo.

[bvssvni]

See rust-lang/rust#21237

[kvark]

I'll deal with it tonight, unless it's fixed by then.

[kvark]

This should be fixed in latest, but the new gfx-rs version has not yet been published.

[kvark]

Gfx v0.1.2 has been published. Please try again with cargo update.

[toqueteos]

I just tried on windows. Still got the same errors as before.

NOPE. I'M AN IDIOT AND WRONG.

[kvark]

Thanks @toqueteos ! I'll have a closer look at this when I'm back at home. We do have the Copy implemented now, and there is even a test for it, so I find it strange that the error is still there.

[toqueteos]

You're welcome @kvark! Just in case I also tried with a fresh clone in a different folder but still no luck. Same 4 nasty errors.

NOPE. I'M AN IDIOT AND WRONG.

[kvark]

I think I found something. Here is your struct:

pub struct Buffer {
    buf: gfx::BufferHandle<Vertex>,
    batch: gfx::batch::RefBatch<ShaderParam>,
}

So even if both gfx parts are Copy, it doesn't make Copy implemented for your Buffer by default. I think you are just missing #[derive(Copy)] for it.

[toqueteos]

Totally right, I forgot to add the missing derive Copy. It does indeed compile again!

Let me copy the MC assets and make a screenshot! YAY for @kvark 👍 ❤️

[kvark]

Thanks! Closing as fixed.

[bvssvni]

This needs a PR, but mac nightlies are delayed so I can't fix it now.

[toqueteos]

@bvssvni Working my ass off on it, also fixing loads of stuff.