Crate option_operations

option-operations provides traits and auto-implementations to improve arithmetic operations usability when dealing with Options.

Example

Dealing with two Options, can lead to verbose expressions:

let lhs = Some(1u64);
let rhs = Some(u64::MAX);

assert_eq!(
    lhs.zip(rhs).map(|(lhs, rhs)| lhs.wrapping_add(rhs)),
    Some(0),
);

Thanks to the trait OptionWrappingAdd we can write:

assert_eq!(
    lhs.opt_wrapping_add(rhs),
    Some(0),
);

The trait can also be used with the inner type:

assert_eq!(
    lhs.opt_wrapping_add(u64::MAX),
    Some(0),
);

assert_eq!(
    1.opt_wrapping_add(rhs),
    Some(0),
);

Alternative to PartialOrd for Option<T>

Another purpose is to workaround the PartiaOrd implementation for Option<T>, which uses the declaration order of the variants for Option. None appearing before Some(_), it results in the following behavior:

let some_0 = Some(0);
let none: Option<u64> = None;

assert_eq!(none.partial_cmp(&some_0), Some(Ordering::Less));
assert_eq!(some_0.partial_cmp(&none), Some(Ordering::Greater));

In some cases, we might consider that None reflects a value which is not defined and thus can not be compared with Some(_).

assert_eq!(none.opt_cmp(&some_0), None);
assert_eq!(some_0.opt_cmp(&none), None);

Re-exports

pub use add::OptionAdd;

pub use add::OptionAddAssign;

pub use add::OptionCheckedAdd;

pub use add::OptionOverflowingAdd;

pub use add::OptionSaturatingAdd;

pub use add::OptionWrappingAdd;

pub use error::Error;

pub use div::OptionCheckedDiv;

pub use div::OptionDiv;

pub use div::OptionDivAssign;

pub use div::OptionOverflowingDiv;

pub use div::OptionWrappingDiv;

pub use eq::OptionEq;

pub use min_max::OptionMinMax;

pub use mul::OptionCheckedMul;

pub use mul::OptionMul;

pub use mul::OptionMulAssign;

pub use mul::OptionOverflowingMul;

pub use mul::OptionSaturatingMul;

pub use mul::OptionWrappingMul;

pub use ord::OptionOrd;

pub use rem::OptionCheckedRem;

pub use rem::OptionOverflowingRem;

pub use rem::OptionRem;

pub use rem::OptionRemAssign;

pub use rem::OptionWrappingRem;

pub use sub::OptionCheckedSub;

pub use sub::OptionOverflowingSub;

pub use sub::OptionSaturatingSub;

pub use sub::OptionSub;

pub use sub::OptionSubAssign;

pub use sub::OptionWrappingSub;

Modules

add

Traits for the addition OptionOperations.

div

Traits for the division OptionOperations.

eq

Trait for the equality OptionOperations.

error

Error type which can be returned by some OptionOperations.

min_max

Traits for the minimun and maximum OptionOperations.

mul

Traits for the multiplication OptionOperations.

ord

Trait for the order OptionOperations.

prelude

rem

Traits for the remainder OptionOperations.

sub

Traits for the substraction OptionOperations.

Traits

OptionOperations

Trait for inner types participating in option-operations.