Struct hyper::header::UserAgent
[−]
[src]
pub struct UserAgent(pub String);
User-Agent header, defined in
RFC7231
The User-Agent header field contains information about the user
agent originating the request, which is often used by servers to help
identify the scope of reported interoperability problems, to work
around or tailor responses to avoid particular user agent
limitations, and for analytics regarding browser or operating system
use. A user agent SHOULD send a User-Agent field in each request
unless specifically configured not to do so.
ABNF
User-Agent = product *( RWS ( product / comment ) )
product = token ["/" product-version]
product-version = token
Example values
CERN-LineMode/2.15 libwww/2.17b3Bunnies
Notes
- The parser does not split the value
Example
use hyper::header::{Headers, UserAgent}; let mut headers = Headers::new(); headers.set(UserAgent("hyper/0.5.2".to_owned()));
Methods from Deref<Target=String>
1.0.0fn into_bytes(self) -> Vec<u8>
Converts a String into a byte vector.
This consumes the String, so we do not need to copy its contents.
Examples
Basic usage:
let s = String::from("hello"); let bytes = s.into_bytes(); assert_eq!(&[104, 101, 108, 108, 111][..], &bytes[..]);
1.7.0fn as_str(&self) -> &str
Extracts a string slice containing the entire string.
1.7.0fn as_mut_str(&mut self) -> &mut str
Extracts a string slice containing the entire string.
1.0.0fn push_str(&mut self, string: &str)
Appends a given string slice onto the end of this String.
Examples
Basic usage:
let mut s = String::from("foo"); s.push_str("bar"); assert_eq!("foobar", s);
1.0.0fn capacity(&self) -> usize
Returns this String's capacity, in bytes.
Examples
Basic usage:
let s = String::with_capacity(10); assert!(s.capacity() >= 10);
1.0.0fn reserve(&mut self, additional: usize)
Ensures that this String's capacity is at least additional bytes
larger than its length.
The capacity may be increased by more than additional bytes if it
chooses, to prevent frequent reallocations.
If you do not want this "at least" behavior, see the reserve_exact()
method.
Panics
Panics if the new capacity overflows usize.
Examples
Basic usage:
let mut s = String::new(); s.reserve(10); assert!(s.capacity() >= 10);
This may not actually increase the capacity:
let mut s = String::with_capacity(10); s.push('a'); s.push('b'); // s now has a length of 2 and a capacity of 10 assert_eq!(2, s.len()); assert_eq!(10, s.capacity()); // Since we already have an extra 8 capacity, calling this... s.reserve(8); // ... doesn't actually increase. assert_eq!(10, s.capacity());
1.0.0fn reserve_exact(&mut self, additional: usize)
Ensures that this String's capacity is additional bytes
larger than its length.
Consider using the reserve() method unless you absolutely know
better than the allocator.
Panics
Panics if the new capacity overflows usize.
Examples
Basic usage:
let mut s = String::new(); s.reserve_exact(10); assert!(s.capacity() >= 10);
This may not actually increase the capacity:
let mut s = String::with_capacity(10); s.push('a'); s.push('b'); // s now has a length of 2 and a capacity of 10 assert_eq!(2, s.len()); assert_eq!(10, s.capacity()); // Since we already have an extra 8 capacity, calling this... s.reserve_exact(8); // ... doesn't actually increase. assert_eq!(10, s.capacity());
1.0.0fn shrink_to_fit(&mut self)
Shrinks the capacity of this String to match its length.
Examples
Basic usage:
let mut s = String::from("foo"); s.reserve(100); assert!(s.capacity() >= 100); s.shrink_to_fit(); assert_eq!(3, s.capacity());
1.0.0fn push(&mut self, ch: char)
Appends the given char to the end of this String.
Examples
Basic usage:
let mut s = String::from("abc"); s.push('1'); s.push('2'); s.push('3'); assert_eq!("abc123", s);
1.0.0fn as_bytes(&self) -> &[u8]
Returns a byte slice of this String's contents.
Examples
Basic usage:
let s = String::from("hello"); assert_eq!(&[104, 101, 108, 108, 111], s.as_bytes());
1.0.0fn truncate(&mut self, new_len: usize)
Shortens this String to the specified length.
Panics
Panics if new_len > current length, or if new_len does not lie on a
char boundary.
Examples
Basic usage:
let mut s = String::from("hello"); s.truncate(2); assert_eq!("he", s);
1.0.0fn pop(&mut self) -> Option<char>
Removes the last character from the string buffer and returns it.
Returns None if this String is empty.
Examples
Basic usage:
let mut s = String::from("foo"); assert_eq!(s.pop(), Some('o')); assert_eq!(s.pop(), Some('o')); assert_eq!(s.pop(), Some('f')); assert_eq!(s.pop(), None);
1.0.0fn remove(&mut self, idx: usize) -> char
Removes a char from this String at a byte position and returns it.
This is an O(n) operation, as it requires copying every element in the
buffer.
Panics
Panics if idx is larger than or equal to the String's length,
or if it does not lie on a char boundary.
Examples
Basic usage:
let mut s = String::from("foo"); assert_eq!(s.remove(0), 'f'); assert_eq!(s.remove(1), 'o'); assert_eq!(s.remove(0), 'o');
1.0.0fn insert(&mut self, idx: usize, ch: char)
Inserts a character into this String at a byte position.
This is an O(n) operation as it requires copying every element in the
buffer.
Panics
Panics if idx is larger than the String's length, or if it does not
lie on a char boundary.
Examples
Basic usage:
let mut s = String::with_capacity(3); s.insert(0, 'f'); s.insert(1, 'o'); s.insert(2, 'o'); assert_eq!("foo", s);
1.0.0unsafe fn as_mut_vec(&mut self) -> &mut Vec<u8>
Returns a mutable reference to the contents of this String.
Safety
This function is unsafe because it does not check that the bytes passed
to it are valid UTF-8. If this constraint is violated, it may cause
memory unsafety issues with future users of the String, as the rest of
the standard library assumes that Strings are valid UTF-8.
Examples
Basic usage:
let mut s = String::from("hello"); unsafe { let vec = s.as_mut_vec(); assert_eq!(&[104, 101, 108, 108, 111][..], &vec[..]); vec.reverse(); } assert_eq!(s, "olleh");
1.0.0fn len(&self) -> usize
Returns the length of this String, in bytes.
Examples
Basic usage:
let a = String::from("foo"); assert_eq!(a.len(), 3);
1.0.0fn is_empty(&self) -> bool
Returns true if this String has a length of zero.
Returns false otherwise.
Examples
Basic usage:
let mut v = String::new(); assert!(v.is_empty()); v.push('a'); assert!(!v.is_empty());
1.0.0fn clear(&mut self)
Truncates this String, removing all contents.
While this means the String will have a length of zero, it does not
touch its capacity.
Examples
Basic usage:
let mut s = String::from("foo"); s.clear(); assert!(s.is_empty()); assert_eq!(0, s.len()); assert_eq!(3, s.capacity());
1.6.0fn drain<R>(&mut self, range: R) -> Drain where R: RangeArgument<usize>
Create a draining iterator that removes the specified range in the string and yields the removed chars.
Note: The element range is removed even if the iterator is not consumed until the end.
Panics
Panics if the starting point or end point do not lie on a char
boundary, or if they're out of bounds.
Examples
Basic usage:
let mut s = String::from("α is alpha, β is beta"); let beta_offset = s.find('β').unwrap_or(s.len()); // Remove the range up until the β from the string let t: String = s.drain(..beta_offset).collect(); assert_eq!(t, "α is alpha, "); assert_eq!(s, "β is beta"); // A full range clears the string s.drain(..); assert_eq!(s, "");
1.4.0fn into_boxed_str(self) -> Box<str>
Converts this String into a Box<str>.
This will drop any excess capacity.
Examples
Basic usage:
let s = String::from("hello"); let b = s.into_boxed_str();