logo
pub enum Preference<T> {
    Any,
    Specific(T),
}
Expand description

A wrapper for types used in header values where wildcard (*) items are allowed but the underlying type does not support them.

For example, we use the language-tags crate for the AcceptLanguage typed header but it does not parse * successfully. On the other hand, the mime crate, used for Accept, has first-party support for wildcard items so this wrapper is not used in those header types.

Variants

Any

A wildcard value.

Specific(T)

A valid T.

Implementations

Returns true if preference is the any/wildcard (*) value.

Returns true if preference is the specific item (T) variant.

Returns reference to value in Specific variant, if it is set.

Consumes the container, returning the value in the Specific variant, if it is set.

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Formats the value using the given formatter. Read more

Formats the value using the given formatter. Read more

The associated error which can be returned from parsing.

Parses a string s to return a value of this type. Read more

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

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

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Compare self to key and return true if they are equal.

Returns the argument unchanged.

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Should always be Self

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

Uses borrowed data to replace owned data, usually by cloning. Read more

Converts the given value to a String. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more