Crate option_operations
source · [−]Expand description
option-operations
provides traits and auto-implementations to
improve arithmetic operations usability when dealing with Option
s.
Example
Dealing with two Option
s, can lead to verbose expressions:
let lhs = Some(1u64);
let rhs = Some(u64::MAX);
assert_eq!(
lhs.zip(rhs).map(|(lhs, rhs)| lhs.saturating_add(rhs)),
Some(u64::MAX),
);
Thanks to the trait OptionSaturatingAdd
we can write:
assert_eq!(
lhs.opt_saturating_add(rhs),
Some(u64::MAX),
);
The trait can also be used with the inner type:
assert_eq!(
lhs.opt_saturating_add(u64::MAX),
Some(u64::MAX),
);
assert_eq!(
1.opt_saturating_add(rhs),
Some(u64::MAX),
);
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);
Of course, this is consistent with other usual comparisons:
assert_eq!(none.opt_lt(&some_0), None);
assert_eq!(none.opt_min(some_0), 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
Traits for the addition OptionOperations
.
Traits for the division OptionOperations
.
Trait for the equality OptionOperations
.
Error type which can be returned by some OptionOperations
.
Traits for the minimun and maximum OptionOperations
.
Traits for the multiplication OptionOperations
.
Trait for the order OptionOperations
.
Traits for the remainder OptionOperations
.
Traits for the substraction OptionOperations
.
Traits
Trait for inner types participating in option-operations
.