Issue 1:
Right now we need to cast to floats in order to print them out.

Issue 2:
This code I used to compile fine with a version of Rust that was about 9 days old. All the comments in the code have been there before, now the code fails to compile at the lines assert_eq!(Foo::id(), "FOO"); and assert_eq!(Bar::id(), "BAR");:

#[test]
fn type_aliases() {
struct Foo {
a: u32,
};
impl Foo {
fn bark(&self) {
println!("Wuff {}", self.a);
}

fn id() -> &'static str {
"FOO"
}
}
assert_eq!(Foo::id(), "FOO");
let f = Foo { a: 1 };
f.bark();

type Bar = Foo;
// assert_eq!(!Bar::id(), "FOO");
// error: unresolved name `Bar::id`
// tests/lang.rs:628 assert_eq!(!Bar::id(), "FOO");
let b = Bar { a: 2 };
b.bark(); // this works though

impl Bar {
// This would add a similarly named implementation, that is difficult to call
// due to ambiguity.
// Interestingly, it also affects Foo, as well as Bar !!
// fn bark(&self) {
// println!("Grrrr {}", self.a);
// }

fn id() -> &'static str {
"BAR"
}
}
// b.bark(); // or f.bark();
// error: multiple applicable methods in scope [E0034]
// tests/lang.rs:625 f.bark();
// ^~~~~~
// tests/lang.rs:615:9: 617:10 note: candidate #1 is defined in an impl for the type `type_aliases::Foo`
// tests/lang.rs:615 fn bark(&self) {
// tests/lang.rs:616 println!("Wuff {}", self.a);
// tests/lang.rs:617 }
// tests/lang.rs:637:9: 639:10 note: candidate #2 is defined in an impl for the type `type_aliases::Foo`
// tests/lang.rs:637 fn bark(&self) {
// tests/lang.rs:638 println!("Grrrr {}", self.a);
assert_eq!(Bar::id(), "BAR");
}

When compiling this now, I get this error, which seems wrong as Bar affects Foo:

tests/lang.rs:636:16: 636:23 error: multiple applicable methods in scope [E0034]
tests/lang.rs:636 assert_eq!(Foo::id(), "FOO");
^~~~~~~
<std macros>:1:1: 9:39 note: in expansion of assert_eq!
tests/lang.rs:636:5: 636:34 note: expansion site
tests/lang.rs:632:9: 634:10 note: candidate #1 is defined in an impl for the type `type_aliases::Foo`
tests/lang.rs:632 fn id() -> &'static str {
tests/lang.rs:633 "FOO"
tests/lang.rs:634 }
tests/lang.rs:655:9: 657:10 note: candidate #2 is defined in an impl for the type `type_aliases::Foo`
tests/lang.rs:655 fn id() -> &'static str {
tests/lang.rs:656 "BAR"
tests/lang.rs:657 }
<std macros>:5:10: 5:20 error: the type of this value must be known in this context
<std macros>:5 if ! ( ( * left_val == * right_val ) && ( * right_val == * left_val ) ) {
^~~~~~~~~~
<std macros>:1:1: 9:39 note: in expansion of assert_eq!
tests/lang.rs:636:5: 636:34 note: expansion site
<std macros>:5:24: 5:35 error: the type of this value must be known in this context
<std macros>:5 if ! ( ( * left_val == * right_val ) && ( * right_val == * left_val ) ) {
^~~~~~~~~~~
<std macros>:1:1: 9:39 note: in expansion of assert_eq!
tests/lang.rs:636:5: 636:34 note: expansion site
tests/lang.rs:670:16: 670:23 error: multiple applicable methods in scope [E0034]
tests/lang.rs:670 assert_eq!(Bar::id(), "BAR");
^~~~~~~
<std macros>:1:1: 9:39 note: in expansion of assert_eq!
tests/lang.rs:670:5: 670:34 note: expansion site
tests/lang.rs:632:9: 634:10 note: candidate #1 is defined in an impl for the type `type_aliases::Foo`
tests/lang.rs:632 fn id() -> &'static str {
tests/lang.rs:633 "FOO"
tests/lang.rs:634 }
tests/lang.rs:655:9: 657:10 note: candidate #2 is defined in an impl for the type `type_aliases::Foo`
tests/lang.rs:655 fn id() -> &'static str {
tests/lang.rs:656 "BAR"
tests/lang.rs:657 }
<std macros>:5:10: 5:20 error: the type of this value must be known in this context
<std macros>:5 if ! ( ( * left_val == * right_val ) && ( * right_val == * left_val ) ) {
^~~~~~~~~~
<std macros>:1:1: 9:39 note: in expansion of assert_eq!
tests/lang.rs:670:5: 670:34 note: expansion site
<std macros>:5:24: 5:35 error: the type of this value must be known in this context
<std macros>:5 if ! ( ( * left_val == * right_val ) && ( * right_val == * left_val ) ) {
^~~~~~~~~~~
<std macros>:1:1: 9:39 note: in expansion of assert_eq!
tests/lang.rs:670:5: 670:34 note: expansion site

Even if this is now desired, I think the compiler message could be improved - it looks similar for the two candidates, and if it wasn't for the code shown below it, I would look like it means the same thing.

Meta

$ rustc --verbose --version
rustc 1.0.0-nightly (4db0b3246 2015-02-25) (built 2015-02-25)
binary: rustc
commit-hash: 4db0b32467535d718d6474de7ae8d1007d900818
commit-date: 2015-02-25
build-date: 2015-02-25
host: x86_64-apple-darwin
release: 1.0.0-nightly