snarkvm_utilities/
defer.rs

1// Copyright (c) 2019-2025 Provable Inc.
2// This file is part of the snarkVM library.
3
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at:
7
8// http://www.apache.org/licenses/LICENSE-2.0
9
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16/// A `Defer` holds a closure that is executed when the instance is dropped.
17pub struct Defer<F: FnOnce()> {
18    f: Option<F>,
19}
20
21impl<F: FnOnce()> Defer<F> {
22    pub fn new(f: F) -> Self {
23        Defer { f: Some(f) }
24    }
25}
26
27impl<F: FnOnce()> Drop for Defer<F> {
28    fn drop(&mut self) {
29        if let Some(f) = self.f.take() {
30            f();
31        }
32    }
33}
34
35#[macro_export]
36macro_rules! defer {
37    ($($body:tt)*) => {
38        let _defer_guard = $crate::Defer::new(|| { $($body)* });
39    };
40}
snarkvm_utilities/defer.rs

snarkvm_utilities/
defer.rs
