Struct hyper::header::CacheControl
[−]
[src]
pub struct CacheControl(pub Vec<CacheDirective>);
Cache-Control
header, defined in RFC7234
The Cache-Control
header field is used to specify directives for
caches along the request/response chain. Such cache directives are
unidirectional in that the presence of a directive in a request does
not imply that the same directive is to be given in the response.
ABNF
Cache-Control = 1#cache-directive
cache-directive = token [ "=" ( token / quoted-string ) ]
Example values
no-cache
private, community="UCI"
max-age=30
Examples
use hyper::header::{Headers, CacheControl, CacheDirective}; let mut headers = Headers::new(); headers.set( CacheControl(vec![CacheDirective::MaxAge(86400u32)]) );
use hyper::header::{Headers, CacheControl, CacheDirective}; let mut headers = Headers::new(); headers.set( CacheControl(vec![ CacheDirective::NoCache, CacheDirective::Private, CacheDirective::MaxAge(360u32), CacheDirective::Extension("foo".to_owned(), Some("bar".to_owned())), ]) );
Methods from Deref<Target=Vec<CacheDirective>>
fn capacity(&self) -> usize
Returns the number of elements the vector can hold without reallocating.
Examples
let vec: Vec<i32> = Vec::with_capacity(10); assert_eq!(vec.capacity(), 10);
fn reserve(&mut self, additional: usize)
Reserves capacity for at least additional
more elements to be inserted
in the given Vec<T>
. The collection may reserve more space to avoid
frequent reallocations.
Panics
Panics if the new capacity overflows usize
.
Examples
let mut vec = vec![1]; vec.reserve(10); assert!(vec.capacity() >= 11);
fn reserve_exact(&mut self, additional: usize)
Reserves the minimum capacity for exactly additional
more elements to
be inserted in the given Vec<T>
. Does nothing if the capacity is already
sufficient.
Note that the allocator may give the collection more space than it
requests. Therefore capacity can not be relied upon to be precisely
minimal. Prefer reserve
if future insertions are expected.
Panics
Panics if the new capacity overflows usize
.
Examples
let mut vec = vec![1]; vec.reserve_exact(10); assert!(vec.capacity() >= 11);
fn shrink_to_fit(&mut self)
Shrinks the capacity of the vector as much as possible.
It will drop down as close as possible to the length but the allocator may still inform the vector that there is space for a few more elements.
Examples
let mut vec = Vec::with_capacity(10); vec.extend([1, 2, 3].iter().cloned()); assert_eq!(vec.capacity(), 10); vec.shrink_to_fit(); assert!(vec.capacity() >= 3);
fn into_boxed_slice(self) -> Box<[T]>
Converts the vector into Box<[T]>.
Note that this will drop any excess capacity. Calling this and
converting back to a vector with into_vec()
is equivalent to calling
shrink_to_fit()
.
fn truncate(&mut self, len: usize)
Shorten a vector, dropping excess elements.
If len
is greater than the vector's current length, this has no
effect.
Examples
let mut vec = vec![1, 2, 3, 4]; vec.truncate(2); assert_eq!(vec, [1, 2]);
fn as_slice(&self) -> &[T]
convert
): waiting on RFC revision
Extracts a slice containing the entire vector.
Equivalent to &s[..]
.
fn as_mut_slice(&mut self) -> &mut [T]
convert
): waiting on RFC revision
Extracts a mutable slice of the entire vector.
Equivalent to &mut s[..]
.
unsafe fn set_len(&mut self, len: usize)
Sets the length of a vector.
This will explicitly set the size of the vector, without actually modifying its buffers, so it is up to the caller to ensure that the vector is actually the specified size.
Examples
let mut v = vec![1, 2, 3, 4]; unsafe { v.set_len(1); }
fn swap_remove(&mut self, index: usize) -> T
Removes an element from anywhere in the vector and return it, replacing it with the last element.
This does not preserve ordering, but is O(1).
Panics
Panics if index
is out of bounds.
Examples
let mut v = vec!["foo", "bar", "baz", "qux"]; assert_eq!(v.swap_remove(1), "bar"); assert_eq!(v, ["foo", "qux", "baz"]); assert_eq!(v.swap_remove(0), "foo"); assert_eq!(v, ["baz", "qux"]);
fn insert(&mut self, index: usize, element: T)
Inserts an element at position index
within the vector, shifting all
elements after position i
one position to the right.
Panics
Panics if index
is greater than the vector's length.
Examples
let mut vec = vec![1, 2, 3]; vec.insert(1, 4); assert_eq!(vec, [1, 4, 2, 3]); vec.insert(4, 5); assert_eq!(vec, [1, 4, 2, 3, 5]);
fn remove(&mut self, index: usize) -> T
Removes and returns the element at position index
within the vector,
shifting all elements after position index
one position to the left.
Panics
Panics if index
is out of bounds.
Examples
let mut v = vec![1, 2, 3]; assert_eq!(v.remove(1), 2); assert_eq!(v, [1, 3]);
fn retain<F>(&mut self, f: F) where F: FnMut(&T) -> bool
Retains only the elements specified by the predicate.
In other words, remove all elements e
such that f(&e)
returns false.
This method operates in place and preserves the order of the retained
elements.
Examples
let mut vec = vec![1, 2, 3, 4]; vec.retain(|&x| x%2 == 0); assert_eq!(vec, [2, 4]);
fn push(&mut self, value: T)
Appends an element to the back of a collection.
Panics
Panics if the number of elements in the vector overflows a usize
.
Examples
let mut vec = vec![1, 2]; vec.push(3); assert_eq!(vec, [1, 2, 3]);
fn pop(&mut self) -> Option<T>
Removes the last element from a vector and returns it, or None
if it
is empty.
Examples
let mut vec = vec![1, 2, 3]; assert_eq!(vec.pop(), Some(3)); assert_eq!(vec, [1, 2]);
fn append(&mut self, other: &mut Vec<T>)
Moves all the elements of other
into Self
, leaving other
empty.
Panics
Panics if the number of elements in the vector overflows a usize
.
Examples
let mut vec = vec![1, 2, 3]; let mut vec2 = vec![4, 5, 6]; vec.append(&mut vec2); assert_eq!(vec, [1, 2, 3, 4, 5, 6]); assert_eq!(vec2, []);
fn drain<R>(&mut self, range: R) -> Drain<T> where R: RangeArgument<usize>
drain
): recently added, matches RFC
Create a draining iterator that removes the specified range in the vector and yields the removed items from start to end. The element range is removed even if the iterator is not consumed until the end.
Note: It is unspecified how many elements are removed from the vector,
if the Drain
value is leaked.
Panics
Panics if the starting point is greater than the end point or if the end point is greater than the length of the vector.
Examples
#![feature(drain)] // Draining using `..` clears the whole vector. let mut v = vec![1, 2, 3]; let u: Vec<_> = v.drain(..).collect(); assert_eq!(v, &[]); assert_eq!(u, &[1, 2, 3]);
fn clear(&mut self)
Clears the vector, removing all values.
Examples
let mut v = vec![1, 2, 3]; v.clear(); assert!(v.is_empty());
fn len(&self) -> usize
Returns the number of elements in the vector.
Examples
let a = vec![1, 2, 3]; assert_eq!(a.len(), 3);
fn is_empty(&self) -> bool
Returns true
if the vector contains no elements.
Examples
let mut v = Vec::new(); assert!(v.is_empty()); v.push(1); assert!(!v.is_empty());
fn split_off(&mut self, at: usize) -> Vec<T>
Splits the collection into two at the given index.
Returns a newly allocated Self
. self
contains elements [0, at)
,
and the returned Self
contains elements [at, len)
.
Note that the capacity of self
does not change.
Panics
Panics if at > len
.
Examples
let mut vec = vec![1,2,3]; let vec2 = vec.split_off(1); assert_eq!(vec, [1]); assert_eq!(vec2, [2, 3]);
fn resize(&mut self, new_len: usize, value: T)
vec_resize
): matches collection reform specification; waiting for dust to settle
Resizes the Vec
in-place so that len()
is equal to new_len
.
Calls either extend()
or truncate()
depending on whether new_len
is larger than the current value of len()
or not.
Examples
#![feature(vec_resize)] let mut vec = vec!["hello"]; vec.resize(3, "world"); assert_eq!(vec, ["hello", "world", "world"]); let mut vec = vec![1, 2, 3, 4]; vec.resize(2, 0); assert_eq!(vec, [1, 2]);
fn push_all(&mut self, other: &[T])
vec_push_all
): likely to be replaced by a more optimized extend
Appends all elements in a slice to the Vec
.
Iterates over the slice other
, clones each element, and then appends
it to this Vec
. The other
vector is traversed in-order.
Examples
#![feature(vec_push_all)] let mut vec = vec![1]; vec.push_all(&[2, 3, 4]); assert_eq!(vec, [1, 2, 3, 4]);
fn dedup(&mut self)
Removes consecutive repeated elements in the vector.
If the vector is sorted, this removes all duplicates.
Examples
let mut vec = vec![1, 2, 2, 3, 2]; vec.dedup(); assert_eq!(vec, [1, 2, 3, 2]);