Struct awc::http::header::EntityTag [−][src]
pub struct EntityTag {
pub weak: bool,
// some fields omitted
}
Expand description
An entity tag, defined in RFC7232
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 1 | ETag 2 | Strong Comparison | Weak Comparison |
---|---|---|---|
W/"1" | W/"1" | no match | match |
W/"1" | W/"2" | no match | no match |
W/"1" | "1" | no match | match |
"1" | "1" | match | match |
Fields
weak: bool
Weakness indicator for the tag
Implementations
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”.
Trait Implementations
type Err = ParseError
type Err = ParseError
The associated error which can be returned from parsing.
type Error = InvalidHeaderValue
type Error = InvalidHeaderValue
The type returned in the event of a conversion error.
Try to convert value to a Header value.
Auto Trait Implementations
impl RefUnwindSafe for EntityTag
impl UnwindSafe for EntityTag
Blanket Implementations
Mutably borrows from an owned value. Read more
Compare self to key
and return true
if they are equal.
Instruments this type with the provided Span
, returning an
Instrumented
wrapper. Read more
Instruments this type with the provided Span
, returning an
Instrumented
wrapper. Read more
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
Attaches the current default Subscriber
to this type, returning a
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wrapper. Read more