scopeguard
==========
Rust crate for a convenient RAII scope guard that will run a given closure when
it goes out of scope, even if the code between panics (assuming unwinding panic).
The `defer!` macro and `guard` are `no_std` compatible (require only core),
but the on unwinding / not on uwinding strategies requires linking to `std`.
Requires Rust 1.20.
Please read the `API documentation here`__
__
https://docs.rs/scopeguard/
|build_status|_ |crates|_
.. |build_status| image::
https://travis-ci.org/bluss/scopeguard.svg
.. _build_status:
https://travis-ci.org/bluss/scopeguard
.. |crates| image::
http://meritbadge.herokuapp.com/scopeguard
.. _crates:
https://crates.io/crates/scopeguard
How to use
----------
.. code:: rust
#[macro_use(defer)] extern crate scopeguard;
use scopeguard::guard;
fn f() {
defer!(println!("Called at return or panic"));
panic!();
}
use std::fs::File;
use std::io::Write;
fn g() {
let f = File::create("newfile.txt").unwrap();
let mut file = guard(f, |f| {
// write file at return or panic
let _ = f.sync_all();
});
// Access the file through the scope guard itself
file.write_all(b"test me\n").unwrap();
}
Recent Changes
--------------
- 1.1.0
- Change macros (``defer!``, ``defer_on_success!`` and ``defer_on_unwind!``)
to accept statements. (by @konsumlamm)
- 1.0.0
- Change the closure type from ``FnMut(&mut T)`` to ``FnOnce(T)``:
Passing the inner value by value instead of a mutable reference is a
breaking change, but allows the guard closure to consume it. (by @tormol)
- Add ``defer_on_success!{}``, ``guard_on_success()`` and ``OnSuccess``
strategy, which triggers when scope is exited *without* panic. It's the
opposite to ``OnUnwind`` / ``guard_on_unwind()`` / ``defer_on_unwind!{}``.
- Add ``ScopeGuard::into_inner()``, which "defuses" the guard and returns the
guarded value. (by @tormol)
- Implement ``Sync`` for guards with non-``Sync`` closures.
- Require Rust 1.20
- 0.3.3
- Use ``#[inline]`` on a few more functions by @stjepang (#14)
- Add examples to crate documentation
- 0.3.2
- Add crate categories
- 0.3.1
- Add ``defer_on_unwind!``, ``Strategy`` trait
- Rename ``Guard`` → ``ScopeGuard``
- Add ``ScopeGuard::with_strategy``.
- ``ScopeGuard`` now implements ``Debug``.
- Require Rust 1.11
- 0.2.0
- Require Rust 1.6
- Use `no_std` unconditionally
- No other changes
- 0.1.2
- Add macro ``defer!()``
