rust-lang/rust — pull request #16636 by Manishearth (2014-08-20 21:15:22+00:00)
Title: Add syntax extensions for lowercasing/uppercasing strings (Fixes #16607)

Testcase:

```
#![feature(macro_rules)]
macro_rules! identify (
($i: ident) => {
let $i = to_lower!(stringify!($i));
}
)

fn main() {
println!("{}", to_lower!("FooBar"))
println!("{}", to_lower!(stringify!(FooBar)))
println!("{}", to_upper!("FooBar"))
println!("{}", to_upper!(stringify!(FooBar)))
identify!(FooBar);
println!("{}",FooBar)
}
```