Enum MayBe 

pub enum MayBe<T> {
    Is(T),
    IsNot,
}

Something that may be of the kind of T.

If a value doesn’t have the kind of T, this will discard the value and provide an MayBe::IsNot. Nevertheless, if the value does have the kind of T but cannot be deserialized by T, this will also fail to deserialize, making this wrapper “shallow”.

For example, structs have the same kind as a JSON object, {}, If the contents of said JSON object don’t match what the struct is expecting, like if the struct Foo { bar: u32 } is being matched, as MayBe<Foo>, against {"bar": ""}, then that is an error. However, matching the same MayBe<Foo> against a JSON array, [] would not lead to an error, but to an MayBe::IsNot.

Can only be used with self-describing formats, like JSON.

Variants

Is(T)

IsNot

Implementations

impl<T> MayBe<T>

pub fn is(&self) -> bool

Returns whether the MayBe contains a T.

pub fn is_not(&self) -> bool

Returns whether the MayBe does not contain a T.

pub fn into_opt(self) -> Option<T>

Converts this MayBe<T> into an Option<T>.

pub fn as_opt(&self) -> Option<&T>

Converts this &MayBe<T> into an Option<&T>.

pub fn as_mut_opt(&mut self) -> Option<&mut T>

Converts this &mut MayBe<T> into an Option<&mut T>.

Trait Implementations

impl<T: Clone> Clone for MayBe<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for MayBe<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de, T: Deserialize<'de>> Deserialize<'de> for MayBe<T>

fn deserialize<D: Deserializer<'de>>(d: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl<T> From<MayBe<T>> for Option<T>

fn from(thing: MayBe<T>) -> Option<T>

Converts to this type from the input type.

impl<T> From<Option<T>> for MayBe<T>

fn from(thing: Option<T>) -> MayBe<T>

Converts to this type from the input type.

impl<T> From<T> for MayBe<T>

fn from(thing: T) -> MayBe<T>

Converts to this type from the input type.

impl<T: Hash> Hash for MayBe<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: Ord> Ord for MayBe<T>

fn cmp(&self, other: &MayBe<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<T: PartialEq> PartialEq for MayBe<T>

fn eq(&self, other: &MayBe<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: PartialOrd> PartialOrd for MayBe<T>

fn partial_cmp(&self, other: &MayBe<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: Copy> Copy for MayBe<T>

impl<T: Eq> Eq for MayBe<T>

impl<T> StructuralPartialEq for MayBe<T>