auto merge of #15493 : brson/rust/tostr, r=pcwalton

This updates https://github.com/rust-lang/rust/pull/15075.

Rename `ToStr::to_str` to `ToString::to_string`. The naive renaming ends up with two `to_string` functions defined on strings in the prelude (the other defined via `collections::str::StrAllocating`). To remedy this I removed `StrAllocating::to_string`, making all conversions from `&str` to `String` go through `Show`. This has a measurable impact on the speed of this conversion, but the sense I get from others is that it's best to go ahead and unify `to_string` and address performance for all `to_string` conversions in `core::fmt`. `String::from_str(...)` still works as a manual fast-path.

Note that the patch was done with a script, and ended up renaming a number of other `*_to_str` functions, particularly inside of rustc. All the ones I saw looked correct, and I didn't notice any additional API breakage.

Closes #15046.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libnum/complex.rs b/src/libnum/complex.rs
index 9ee80d283cf..f4a3ac97a4e 100644
--- a/src/libnum/complex.rs
+++ b/src/libnum/complex.rs
@@ -347,9 +347,9 @@ mod test {
     }
 
     #[test]
-    fn test_to_str() {
+    fn test_to_string() {
         fn test(c : Complex64, s: String) {
-            assert_eq!(c.to_str(), s);
+            assert_eq!(c.to_string(), s);
         }
         test(_0_0i, "0+0i".to_string());
         test(_1_0i, "1+0i".to_string());