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, 5 deletions

diff --git a/src/libstd/dynamic_lib.rs b/src/libstd/dynamic_lib.rs
index 728875ce260..86283f03381 100644
--- a/src/libstd/dynamic_lib.rs
+++ b/src/libstd/dynamic_lib.rs
@@ -209,13 +209,11 @@ mod test {
 #[cfg(target_os = "ios")]
 #[cfg(target_os = "freebsd")]
 pub mod dl {
-    use prelude::*;
 
     use c_str::{CString, ToCStr};
     use libc;
     use ptr;
     use result::*;
-    use str::StrAllocating;
     use string::String;
 
     pub unsafe fn open_external<T: ToCStr>(filename: T) -> *mut u8 {
@@ -243,9 +241,8 @@ pub mod dl {
             let ret = if ptr::null() == last_error {
                 Ok(result)
             } else {
-                Err(CString::new(last_error, false).as_str()
-                                                   .unwrap()
-                                                   .to_string())
+                Err(String::from_str(CString::new(last_error, false).as_str()
+                    .unwrap()))
             };
 
             ret