Re-export RendererError

[fschutt]

Right now the RendererError that is returned from Renderer::render() is not accessible in the API - while it's marked as pub, it is stored in the private renderer.rs module and therefore I can't access the enum fields from outside of this crate.

Something like pub use renderer::RendererError in the lib.rs would be nice.

webrender/webrender/src/renderer.rs

Lines 1592 to 1597 in efba6f2

	pub enum RendererError {
	Shader(ShaderError),
	Thread(std::io::Error),
	Resource(ResourceCacheError),
	MaxTextureSize,
	}

https://docs.rs/webrender/0.60.0/webrender/struct.Renderer.html#method.render - note that the returned Vec<RendererError> isn't clickable, meaning that it's not publicly accessible.

[kvark]

That's a good case where I'd expect the compiler to complain because a private type is exposed in public API. I agree we need to re-expeort it.

[fschutt]

Yeah, the problem is that the type is public, but it's inside of a private module - so Rust allows it to be returned from public functions, but the type can't be constructed or accessed from outside. There was a discussion about this behaviour: https://internals.rust-lang.org/t/pre-rfc-warn-about-inaccessible-types-in-public-function-signatures/5156 - but there seem to be some API cases where these things seem to be necessary, so I doubt it'll change (a warning would be nice, though). The only way I've been able to work around this in my APIs is to run cargo doc and look (manually, but it could be scripted) for these "black" return types.

[fschutt]

While I'm at it, ResourceUpdate could also implement Debug and PartialEq, so that it's printable and can be used in unit tests.