4 releases (breaking)
new 0.4.0 | Oct 26, 2024 |
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0.3.0 | Dec 10, 2023 |
0.2.0 | Dec 9, 2023 |
0.1.0 | Dec 6, 2023 |
0.0.0 |
|
#2433 in Rust patterns
53 downloads per month
Used in 3 crates
9KB
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I/O adapters
This crate provides adapters to compose writeable traits in the standard library. The following conversions are available:
fmt::Write
->io::Write
io::Write
->hash::Hasher
Use case
Suppose you are writing a function which emits human-readable data in a zero-alloc way. The best interface looks something like this:
fn foo<Out: fmt::Write>(mut output: Out, ...) {
// Do stuff
writeln!(output, "My computation: {result}").unwrap();
}
Notice the use of fmt::Write
: using this trait provides a type-system guarantee that the data
written is valid UTF-8, hence why it should be preferred over io::Write
.
Now users of this API can gather data into a String
, provide their own fmt::Write
implementation, etc. The problem you'll run into is if you'd like to send the output of this
function to stdout: there is no built-in way to do so! That's where this crate comes in by providing
an adapter, so you can write the following:
foo(&mut io::stdout().write_adapter());