auto merge of #13440 : huonw/rust/strbuf, r=alexcrichton

libstd: Implement `StrBuf`, a new string buffer type like `Vec`, and port all code over to use it.

Rebased & tests-fixed version of https://github.com/mozilla/rust/pull/13269

1 files changed, 3 insertions, 3 deletions

diff --git a/src/libsyntax/ext/deriving/show.rs b/src/libsyntax/ext/deriving/show.rs
index 1c80fb9ced2..067958e4bde 100644
--- a/src/libsyntax/ext/deriving/show.rs
+++ b/src/libsyntax/ext/deriving/show.rs
@@ -15,10 +15,10 @@ use ext::format;
 use ext::base::ExtCtxt;
 use ext::build::AstBuilder;
 use ext::deriving::generic::*;
-
 use parse::token;
 
 use collections::HashMap;
+use std::strbuf::StrBuf;
 
 pub fn expand_deriving_show(cx: &mut ExtCtxt,
                             span: Span,
@@ -68,7 +68,7 @@ fn show_substructure(cx: &mut ExtCtxt, span: Span,
         }
     };
 
-    let mut format_string = token::get_ident(name).get().to_owned();
+    let mut format_string = StrBuf::from_str(token::get_ident(name).get());
     // the internal fields we're actually formatting
     let mut exprs = Vec::new();
 
@@ -129,7 +129,7 @@ fn show_substructure(cx: &mut ExtCtxt, span: Span,
     let write_call = cx.expr_call_global(span, std_write, vec!(buf, cx.expr_ident(span, args)));
     let format_closure = cx.lambda_expr(span, vec!(args), write_call);
 
-    let s = token::intern_and_get_ident(format_string);
+    let s = token::intern_and_get_ident(format_string.as_slice());
     let format_string = cx.expr_str(span, s);
 
     // phew, not our responsibility any more!