From e423fcf0e0166da55f88233e0be5eacba55bc0bc Mon Sep 17 00:00:00 2001 From: Alex Crichton Date: Fri, 12 Dec 2014 10:59:41 -0800 Subject: std: Enforce Unicode in fmt::Writer This commit is an implementation of [RFC 526][rfc] which is a change to alter the definition of the old `fmt::FormatWriter`. The new trait, renamed to `Writer`, now only exposes one method `write_str` in order to guarantee that all implementations of the formatting traits can only produce valid Unicode. [rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0526-fmt-text-writer.md One of the primary improvements of this patch is the performance of the `.to_string()` method by avoiding an almost-always redundant UTF-8 check. This is a breaking change due to the renaming of the trait as well as the loss of the `write` method, but migration paths should be relatively easy: * All usage of `write` should move to `write_str`. If truly binary data was being written in an implementation of `Show`, then it will need to use a different trait or an altogether different code path. * All usage of `write!` should continue to work as-is with no modifications. * All usage of `Show` where implementations just delegate to another should continue to work as-is. [breaking-change] Closes #20352 --- src/libsyntax/ast.rs | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'src/libsyntax') diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs index 12432c8c78f..4606e70d83b 100644 --- a/src/libsyntax/ast.rs +++ b/src/libsyntax/ast.rs @@ -1662,6 +1662,7 @@ mod test { use serialize; use codemap::*; use super::*; + use std::fmt; // are ASTs encodable? #[test] @@ -1687,6 +1688,6 @@ mod test { exported_macros: Vec::new(), }; // doesn't matter which encoder we use.... - let _f = &e as &serialize::Encodable; + let _f = &e as &serialize::Encodable; } } -- cgit 1.4.1-3-g733a5