Struct OptionGuardMut

pub struct OptionGuardMut<'a, T: 'a> { /* private fields */ }

A value taken from an Option<T>. OptionGuardMut<T> dereferences to a T, and the inner T can be moved out with OptionGuardMut::into_inner. When dropped, the OptionGuardMut moves the taken value back into the Option it came from.

Examples

Take a value from an option, which is automatically returned:

let mut thing = Some(5);
 
{
    let mut stolen = thing.steal_mut();
 
    assert_eq!(*stolen, 5);
 
    *stolen = 6;
}
 
assert_eq!(thing, Some(6));

If the guard is consumed, the value is never returned.

let mut thing = Some(5);
 
{
    // Keep the thing!
    let stolen = thing.steal_mut().into_inner();
 
    assert_eq!(stolen, 5);
}
 
assert_eq!(thing, None);

Calling steal_mut on a None immediately panics:

let mut thing: Option<i32> = None;
 
// Panics here!
thing.steal_mut();

Implementations

impl<'a, T> OptionGuardMut<'a, T>

pub fn into_inner(self) -> T

Keep the value stolen from the Option and do not return it.

Trait Implementations

impl<'a, T> Deref for OptionGuardMut<'a, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<'a, T> DerefMut for OptionGuardMut<'a, T>

fn deref_mut(&mut self) -> &mut T

Mutably dereferences the value.

impl<'a, T> Drop for OptionGuardMut<'a, T>

fn drop(&mut self)

Executes the destructor for this type.