Feature gate: #![feature(file_buffered)]

This is a tracking issue for File constructors that return files wrapped with a buffer.

In addition to the light convenience, these are intended to raise visibility that buffering is something you should consider when opening a file, since unbuffered I/O is a common performance footgun to Rust newcomers.

Public API

// std::fs

impl File {
    pub fn open_buffered<P: AsRef<Path>>(path: P) -> io::Result<io::BufReader<File>>;
    pub fn create_buffered<P: AsRef<Path>>(path: P) -> io::Result<io::BufWriter<File>>;
}

Steps / History

• API Change Proposal (ACP): Add File constructors that nudge people toward buffered I/O libs-team#446
• Implementation: Add File constructors that return files wrapped with a buffer #130803
• Final comment period (FCP)¹
• Stabilization PR

Unresolved Questions

• None yet.