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pub struct EntityTag {
    pub weak: bool,
    /* private fields */
}
Expand description

An entity tag, defined in RFC 7232 §2.3

An entity tag consists of a string enclosed by two literal double quotes. Preceding the first double quote is an optional weakness indicator, which always looks like W/. Examples for valid tags are "xyzzy" and W/"xyzzy".

ABNF

entity-tag = [ weak ] opaque-tag
weak       = %x57.2F ; "W/", case-sensitive
opaque-tag = DQUOTE *etagc DQUOTE
etagc      = %x21 / %x23-7E / obs-text
           ; VCHAR except double quotes, plus obs-text

Comparison

To check if two entity tags are equivalent in an application always use the strong_eq or weak_eq methods based on the context of the Tag. Only use == to check if two tags are identical.

The example below shows the results for a set of entity-tag pairs and both the weak and strong comparison function results:

ETag 1ETag 2Strong ComparisonWeak Comparison
W/"1"W/"1"no matchmatch
W/"1"W/"2"no matchno match
W/"1""1"no matchmatch
"1""1"matchmatch

Fields

weak: bool

Weakness indicator for the tag

Implementations

Constructs a new EntityTag.

Panics

If the tag contains invalid characters.

Constructs a new weak EntityTag.

Panics

If the tag contains invalid characters.

Constructs a new strong EntityTag.

Panics

If the tag contains invalid characters.

Get the tag.

Set the tag.

Panics

If the tag contains invalid characters.

For strong comparison two entity-tags are equivalent if both are not weak and their opaque-tags match character-by-character.

For weak comparison two entity-tags are equivalent if their opaque-tags match character-by-character, regardless of either or both being tagged as “weak”.

The inverse of EntityTag.strong_eq().

The inverse of EntityTag.weak_eq().

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

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

This method tests for !=.

The type returned in the event of a conversion error.

Try to convert value to a HeaderValue.

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

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