From df6225b8c3c981a686e5590dc59a7a5865476862 Mon Sep 17 00:00:00 2001 From: Alex Crichton Date: Sun, 20 Oct 2013 15:42:24 -0700 Subject: Don't allocate a string when calling println Instead use format_args! to pass around a struct to pass along into std::fmt --- src/libstd/rt/io/stdio.rs | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'src/libstd/rt') diff --git a/src/libstd/rt/io/stdio.rs b/src/libstd/rt/io/stdio.rs index e3ca148862f..e6dd9a48099 100644 --- a/src/libstd/rt/io/stdio.rs +++ b/src/libstd/rt/io/stdio.rs @@ -8,6 +8,7 @@ // option. This file may not be copied, modified, or distributed // except according to those terms. +use fmt; use libc; use option::{Option, Some, None}; use result::{Ok, Err}; @@ -56,7 +57,9 @@ pub fn stderr() -> StdWriter { pub fn print(s: &str) { // XXX: need to see if not caching stdin() is the cause of performance // issues, it should be possible to cache a stdout handle in each Task - // and then re-use that across calls to print/println + // and then re-use that across calls to print/println. Note that the + // resolution of this comment will affect all of the prints below as + // well. stdout().write(s.as_bytes()); } @@ -68,6 +71,20 @@ pub fn println(s: &str) { out.write(['\n' as u8]); } +/// Similar to `print`, but takes a `fmt::Arguments` structure to be compatible +/// with the `format_args!` macro. +pub fn print_args(fmt: &fmt::Arguments) { + let mut out = stdout(); + fmt::write(&mut out as &mut Writer, fmt); +} + +/// Similar to `println`, but takes a `fmt::Arguments` structure to be +/// compatible with the `format_args!` macro. +pub fn println_args(fmt: &fmt::Arguments) { + let mut out = stdout(); + fmt::writeln(&mut out as &mut Writer, fmt); +} + /// Representation of a reader of a standard input stream pub struct StdReader { priv inner: ~RtioFileStream -- cgit 1.4.1-3-g733a5