Implement Ord, PartialOrd, Eq, PartialEq by hand

[TyOverby]

There is a bug in rustc that causes code explosion when auto-implementing PartialOrd. rust-lang/rust#15375

Until those issues are fixed, I've implemented them by hand.

Closes #467

[TyOverby]

The travis build is failing due to an issue with Cargo.

[gmorenz]

This is an issue with Cargo not piston, isn't it?

The PR compiles and runs on my machine, I have the latest nightly installed.

[TyOverby]

@gmorenz: For some reason, I keep switching those words up. You were right; I've edited my comment.

[indiv0]

The hammer.rs issue has been fixed. Next steps for this PR?

[gmorenz]

I think it can be merged... I don't think I am supposed to be merging pull requests unfortunately, though I technical have the ability to. If you need to build against this (or any non merged pull request) in the meantime you can check out the PR locally, and use [dependencies.piston] git = "file:///location/of/repo" in your projects Cargo.toml.

[indiv0]

Trying to build with this PR, I get the following error:

projects/rust-ssb [ cargo build --verbose                      master * ] 8:44 PM
   Compiling piston v0.0.0 (file:/home/indiv0/projects/rust-ssb/lib/piston)
       Fresh codegen v0.0.1 (https://github.com/AngryLawyer/rust-sdl2)
       Fresh image v0.0.0 (https://github.com/PistonDevelopers/rust-image)
       Fresh graphics v0.0.0 (https://github.com/PistonDevelopers/rust-graphics)
       Fresh gl v0.0.1 (https://github.com/bjz/gl-rs)
       Fresh sdl2 v0.0.1 (https://github.com/AngryLawyer/rust-sdl2)
       Fresh opengl_graphics v0.0.0 (https://github.com/PistonDevelopers/opengl_graphics)
Could not execute process `rustc src/lib.rs --crate-type lib --out-dir /media/projects/rust-ssb/target/deps -L /media/projects/rust-ssb/target/deps -L /media/projects/rust-ssb/target/deps` (status=101)
--- stderr
src/keyboard.rs:266:1: 271:2 error: not all trait methods implemented, missing: `partial_cmp`
src/keyboard.rs:266 impl PartialOrd for Key {
src/keyboard.rs:267     #[inline(always)]
src/keyboard.rs:268     fn lt(&self, rhs: &Key) -> bool {
src/keyboard.rs:269         self.code() < rhs.code()
src/keyboard.rs:270     }
src/keyboard.rs:271 }
src/event.rs:13:17: 13:30 error: type `keyboard::Key` does not implement any method in scope named `partial_cmp`
src/event.rs:13     KeyReleased(keyboard::Key),
                                ^~~~~~~~~~~~~
src/event.rs:8:30: 8:40 note: in expansion of #[deriving(PartialOrd)]
src/event.rs:13:17: 13:30 note: expansion site
src/event.rs:15:16: 15:29 error: type `keyboard::Key` does not implement any method in scope named `partial_cmp`
src/event.rs:15     KeyPressed(keyboard::Key),
                               ^~~~~~~~~~~~~
src/event.rs:8:30: 8:40 note: in expansion of #[deriving(PartialOrd)]
src/event.rs:15:16: 15:29 note: expansion site
error: aborting due to 3 previous errors


Caused by:
  Could not execute process `rustc src/lib.rs --crate-type lib --out-dir /media/projects/rust-ssb/target/deps -L /media/projects/rust-ssb/target/deps -L /media/projects/rust-ssb/target/deps` (status=101)
--- stderr
src/keyboard.rs:266:1: 271:2 error: not all trait methods implemented, missing: `partial_cmp`
src/keyboard.rs:266 impl PartialOrd for Key {
src/keyboard.rs:267     #[inline(always)]
src/keyboard.rs:268     fn lt(&self, rhs: &Key) -> bool {
src/keyboard.rs:269         self.code() < rhs.code()
src/keyboard.rs:270     }
src/keyboard.rs:271 }
src/event.rs:13:17: 13:30 error: type `keyboard::Key` does not implement any method in scope named `partial_cmp`
src/event.rs:13     KeyReleased(keyboard::Key),
                                ^~~~~~~~~~~~~
src/event.rs:8:30: 8:40 note: in expansion of #[deriving(PartialOrd)]
src/event.rs:13:17: 13:30 note: expansion site
src/event.rs:15:16: 15:29 error: type `keyboard::Key` does not implement any method in scope named `partial_cmp`
src/event.rs:15     KeyPressed(keyboard::Key),
                               ^~~~~~~~~~~~~
src/event.rs:8:30: 8:40 note: in expansion of #[deriving(PartialOrd)]
src/event.rs:15:16: 15:29 note: expansion site
error: aborting due to 3 previous errors

[indiv0]

So partial_cmp needs to be implemented for Keyboard as well.

[gmorenz]

Your error message doesn't seem to be coming from a version of piston including this pull request, e.g. on line 266 you have impl PartialOrd for key but this pull request has a blank line.

For reference the following sequence of commands successfully builds piston from scratch with this PR for me:

git clone https://github.com/pistondevelopers/piston
cd piston
git fetch origin pull/470/head:partialfix
git checkout partialfix
cargo build

[indiv0]

Yeah it worked with your instructions. My bad :P