# scopeguard::ScopeGuard - Rust
`ScopeGuard` is a scope guard that may own a protected value.
Keywords: rust, rustlang, rust-lang, ScopeGuard

# Struct scopeguard::ScopeGuard [−] [src]

    pub struct ScopeGuard<T, F, S = Always> where
        F: FnOnce(T),
        S: Strategy,  { /* fields omitted */ }

`ScopeGuard` is a scope guard that may own a protected value.

If you place a guard in a local variable, the closure can run regardless how you leave the scope — through regular return or panic (except if panic or other code aborts; so as long as destructors run). It is run only once.

The `S` parameter for `Strategy` determines if the closure actually runs.

The guard’s closure will be called with the held value in the destructor.

The `ScopeGuard` implements `Deref` so that you can access the inner value.

## Implementations

### `impl<T, F, S> ScopeGuard<T, F, S> where
F: FnOnce(T),
S: Strategy,` [src]

#### `pub fn with_strategy(v: T, dropfn: F) -> ScopeGuard<T, F, S>` [src]

Create a `ScopeGuard` that owns `v` (accessible through deref) and calls `dropfn` when its destructor runs.

The `Strategy` decides whether the scope guard’s closure should run.

#### `pub fn into_inner(guard: Self) -> T` [src]

“Defuse” the guard and extract the value without calling the closure.

    extern crate scopeguard;

    use scopeguard::{guard, ScopeGuard};

    fn conditional() -> bool { true }

    fn main() {
        let mut guard = guard(Vec::new(), |mut v| v.clear());
        guard.push(1);

        if conditional() {
            // a condition maybe makes us decide to
            // “defuse” the guard and get back its inner parts
            let value = ScopeGuard::into_inner(guard);
        } else {
            // guard still exists in this branch
        }
    }

## Trait Implementations

### `impl<T, F, S> Debug for ScopeGuard<T, F, S> where
T: Debug,
F: FnOnce(T),
S: Strategy,` [src]

#### `fn fmt(&self, f: &mut Formatter<'_>) -> Result` [src]

Formats the value using the given formatter. Read more

### `impl<T, F, S> Deref for ScopeGuard<T, F, S> where
F: FnOnce(T),
S: Strategy,` [src]

#### `type Target = T`

The resulting type after dereferencing.

#### `fn deref(&self) -> &T` [src]

Dereferences the value.

### `impl<T, F, S> DerefMut for ScopeGuard<T, F, S> where
F: FnOnce(T),
S: Strategy,` [src]

#### `fn deref_mut(&mut self) -> &mut T` [src]

Mutably dereferences the value.

### `impl<T, F, S> Drop for ScopeGuard<T, F, S> where
F: FnOnce(T),
S: Strategy,` [src]

#### `fn drop(&mut self)` [src]

Executes the destructor for this type. Read more

### `impl<T, F, S> Sync for ScopeGuard<T, F, S> where
T: Sync,
F: FnOnce(T),
S: Strategy,` [src]

## Auto Trait Implementations

### `impl<T, F, S> Send for ScopeGuard<T, F, S> where
F: Send,
T: Send,`

### `impl<T, F, S> Unpin for ScopeGuard<T, F, S> where
F: Unpin,
T: Unpin,`

## Blanket Implementations

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `pub fn type_id(&self) -> TypeId` [src]

Gets the `TypeId` of `self`. Read more

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow(&self) -> &T` [src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow_mut(&mut self) -> &mut T` [src]

Mutably borrows from an owned value. Read more

### `impl<T> From<T> for T` [src]

#### `pub fn from(t: T) -> T` [src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `pub fn into(self) -> U` [src]

Performs the conversion.

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>` [src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.

#### `pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>` [src]

Performs the conversion.