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//! Non-blocking lookup result type.
/// Represents the result of a non-blocking read.
#[derive(Debug)]
pub enum TryResult<R> {
/// The value was present and the lock was obtained.
Present(R),
/// The shard wasn't locked and the value wasn't present.
Absent,
/// The shard was locked.
Locked,
}
impl<R> TryResult<R> {
/// Returns `true` if the entry was found and the lock was acquired.
pub fn is_present(&self) -> bool {
matches!(self, TryResult::Present(_))
}
/// Returns `true` if the shard was accessible but the key was not found.
pub fn is_absent(&self) -> bool {
matches!(self, TryResult::Absent)
}
/// Returns `true` if the shard was locked and the attempt was aborted.
pub fn is_locked(&self) -> bool {
matches!(self, TryResult::Locked)
}
/// Panics if the result is not `Present`, otherwise returns the inner value.
pub fn unwrap(self) -> R {
match self {
TryResult::Present(r) => r,
TryResult::Locked => panic!("Called unwrap() on TryResult::Locked"),
TryResult::Absent => panic!("Called unwrap() on TryResult::Absent"),
}
}
/// Returns `Some(r)` if `Present`, otherwise `None`.
pub fn try_unwrap(self) -> Option<R> {
match self {
TryResult::Present(r) => Some(r),
_ => None,
}
}
}