WIP HeaderValue: make Cow<'static, str> #335
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This allows HeaderValue to borrow `'static` strings, rather than make allocations. Unfortunately, we can't specialize `TryFrom` or `From`, so this also adds a new crate-only `from_static_str() -> HeaderValue`.
| @@ -11,7 +12,7 @@ use crate::Mime; | |||
| /// A header value. | |||
| #[derive(Clone, Eq, PartialEq, Hash)] | |||
| pub struct HeaderValue { | |||
| inner: String, | |||
| inner: Cow<'static, str>, | |||
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why not pub struct HeaderValue<'a> { inner: Cow<'a, str> } and just use HeaderValue<'static> where we need it to be 'static?
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@jbr That'd make the API a little more awkward to use, and would potentially be a backwards-compatibility issue.
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Most header names (and many header values) will be short; we might want to use something like |
trillium's header name implementation does something like this, using smartcow which is just a cow for smartstring. However it might also make sense to use some sort of string interning library because there are only a handful of header names used in reality and they're repeated across requests |
This allows HeaderValue to borrow
'staticstrings, rather than make allocations.Unfortunately, we can't specialize
TryFromorFrom, so this also adds a new crate-onlyfrom_static_str() -> HeaderValue.