Trait gut::index::CheckedIndex

pub trait CheckedIndex<T>: From<T> + Into<Option<T>> + Add<Self, Output = Self, Output = Self> + Add<T> + Sub<Self, Output = Self, Output = Self> + Sub<T> + Mul<T, Output = Self> + Div<T, Output = Self> + Rem<T, Output = Self> {
    fn invalid() -> Self;
    fn is_valid(&self) -> bool;
    fn unwrap(self) -> T;
    fn expect(self, msg: &str) -> T;
    fn map<F>(self, f: F) -> Self
    where
        F: FnOnce(T) -> T;
    fn map_or<U, F>(self, default: U, f: F) -> U
    where
        F: FnOnce(T) -> U;
    fn into_inner(self) -> T;
}

A trait that defines what it means for an index to be a checked index. In other words implementers are indices that are checked for validity in some way.

Required methods

fn invalid() -> Self

Construct an invalid index.

fn is_valid(&self) -> bool

Check if the index is valid.

fn unwrap(self) -> T

Convert the index into its underlying integer type. Panic if index is invalid.

fn expect(self, msg: &str) -> T

Convert the index into its underlying integer type. In case of failure, report the given message.

fn map<F>(self, f: F) -> Self where
    F: FnOnce(T) -> T, 

Map the underlying integer type. This allows restricting operations to valid indices only.

fn map_or<U, F>(self, default: U, f: F) -> U where
    F: FnOnce(T) -> U, 

Map the underlying integer type. If the index is invalid, output the provided default.

fn into_inner(self) -> T

Produce the raw inner type without checking.

Implementors

impl CheckedIndex<usize> for Index