# Struct hyper::header::ContentLength
[−]
[src]

pub struct ContentLength(pub u64);

`Content-Length`

header, defined in
RFC7230

When a message does not have a `Transfer-Encoding`

header field, a
Content-Length header field can provide the anticipated size, as a
decimal number of octets, for a potential payload body. For messages
that do include a payload body, the Content-Length field-value
provides the framing information necessary for determining where the
body (and message) ends. For messages that do not include a payload
body, the Content-Length indicates the size of the selected
representation.

# ABNF

```
Content-Length = 1*DIGIT
```

# Example values

`3495`

# Example

use hyper::header::{Headers, ContentLength}; let mut headers = Headers::new(); headers.set(ContentLength(1024u64));

## Methods from Deref<Target=u64>

`fn count_ones(self) -> u32`

Returns the number of ones in the binary representation of `self`

.

# Examples

Basic usage:

let n = 0b01001100u8; assert_eq!(n.count_ones(), 3);

`fn count_zeros(self) -> u32`

Returns the number of zeros in the binary representation of `self`

.

# Examples

Basic usage:

let n = 0b01001100u8; assert_eq!(n.count_zeros(), 5);

`fn leading_zeros(self) -> u32`

Returns the number of leading zeros in the binary representation
of `self`

.

# Examples

Basic usage:

let n = 0b0101000u16; assert_eq!(n.leading_zeros(), 10);

`fn trailing_zeros(self) -> u32`

Returns the number of trailing zeros in the binary representation
of `self`

.

# Examples

Basic usage:

let n = 0b0101000u16; assert_eq!(n.trailing_zeros(), 3);

`fn rotate_left(self, n: u32) -> u64`

Shifts the bits to the left by a specified amount, `n`

,
wrapping the truncated bits to the end of the resulting integer.

# Examples

Basic usage:

let n = 0x0123456789ABCDEFu64; let m = 0x3456789ABCDEF012u64; assert_eq!(n.rotate_left(12), m);

`fn rotate_right(self, n: u32) -> u64`

Shifts the bits to the right by a specified amount, `n`

,
wrapping the truncated bits to the beginning of the resulting
integer.

# Examples

Basic usage:

let n = 0x0123456789ABCDEFu64; let m = 0xDEF0123456789ABCu64; assert_eq!(n.rotate_right(12), m);

`fn swap_bytes(self) -> u64`

Reverses the byte order of the integer.

# Examples

Basic usage:

let n = 0x0123456789ABCDEFu64; let m = 0xEFCDAB8967452301u64; assert_eq!(n.swap_bytes(), m);

`fn to_be(self) -> u64`

Converts `self`

to big endian from the target's endianness.

On big endian this is a no-op. On little endian the bytes are swapped.

# Examples

Basic usage:

let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "big") { assert_eq!(n.to_be(), n) } else { assert_eq!(n.to_be(), n.swap_bytes()) }

`fn to_le(self) -> u64`

Converts `self`

to little endian from the target's endianness.

On little endian this is a no-op. On big endian the bytes are swapped.

# Examples

Basic usage:

let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "little") { assert_eq!(n.to_le(), n) } else { assert_eq!(n.to_le(), n.swap_bytes()) }

`fn checked_add(self, other: u64) -> Option<u64>`

Checked integer addition. Computes `self + other`

, returning `None`

if overflow occurred.

# Examples

Basic usage:

assert_eq!(5u16.checked_add(65530), Some(65535)); assert_eq!(6u16.checked_add(65530), None);

`fn checked_sub(self, other: u64) -> Option<u64>`

Checked integer subtraction. Computes `self - other`

, returning
`None`

if underflow occurred.

# Examples

Basic usage:

assert_eq!(1u8.checked_sub(1), Some(0)); assert_eq!(0u8.checked_sub(1), None);

`fn checked_mul(self, other: u64) -> Option<u64>`

Checked integer multiplication. Computes `self * other`

, returning
`None`

if underflow or overflow occurred.

# Examples

Basic usage:

assert_eq!(5u8.checked_mul(51), Some(255)); assert_eq!(5u8.checked_mul(52), None);

`fn checked_div(self, other: u64) -> Option<u64>`

Checked integer division. Computes `self / other`

, returning `None`

if `other == 0`

or the operation results in underflow or overflow.

# Examples

Basic usage:

assert_eq!(128u8.checked_div(2), Some(64)); assert_eq!(1u8.checked_div(0), None);

`fn checked_rem(self, other: u64) -> Option<u64>`

Checked integer remainder. Computes `self % other`

, returning `None`

if `other == 0`

or the operation results in underflow or overflow.

# Examples

Basic usage:

assert_eq!(5u32.checked_rem(2), Some(1)); assert_eq!(5u32.checked_rem(0), None);

`fn checked_neg(self) -> Option<u64>`

Checked negation. Computes `-self`

, returning `None`

unless `self == 0`

.

Note that negating any positive integer will overflow.

# Examples

Basic usage:

assert_eq!(0u32.checked_neg(), Some(0)); assert_eq!(1u32.checked_neg(), None);

`fn checked_shl(self, rhs: u32) -> Option<u64>`

Checked shift left. Computes `self << rhs`

, returning `None`

if `rhs`

is larger than or equal to the number of bits in `self`

.

# Examples

Basic usage:

assert_eq!(0x10u32.checked_shl(4), Some(0x100)); assert_eq!(0x10u32.checked_shl(33), None);

`fn checked_shr(self, rhs: u32) -> Option<u64>`

Checked shift right. Computes `self >> rhs`

, returning `None`

if `rhs`

is larger than or equal to the number of bits in `self`

.

# Examples

Basic usage:

assert_eq!(0x10u32.checked_shr(4), Some(0x1)); assert_eq!(0x10u32.checked_shr(33), None);

`fn saturating_add(self, other: u64) -> u64`

Saturating integer addition. Computes `self + other`

, saturating at
the numeric bounds instead of overflowing.

# Examples

Basic usage:

assert_eq!(100u8.saturating_add(1), 101); assert_eq!(200u8.saturating_add(127), 255);

`fn saturating_sub(self, other: u64) -> u64`

Saturating integer subtraction. Computes `self - other`

, saturating
at the numeric bounds instead of overflowing.

# Examples

Basic usage:

assert_eq!(100u8.saturating_sub(27), 73); assert_eq!(13u8.saturating_sub(127), 0);

`fn saturating_mul(self, other: u64) -> u64`

Saturating integer multiplication. Computes `self * other`

,
saturating at the numeric bounds instead of overflowing.

# Examples

Basic usage:

use std::u32; assert_eq!(100u32.saturating_mul(127), 12700); assert_eq!((1u32 << 23).saturating_mul(1 << 23), u32::MAX);

`fn wrapping_add(self, rhs: u64) -> u64`

Wrapping (modular) addition. Computes `self + other`

,
wrapping around at the boundary of the type.

# Examples

Basic usage:

assert_eq!(200u8.wrapping_add(55), 255); assert_eq!(200u8.wrapping_add(155), 99);

`fn wrapping_sub(self, rhs: u64) -> u64`

Wrapping (modular) subtraction. Computes `self - other`

,
wrapping around at the boundary of the type.

# Examples

Basic usage:

assert_eq!(100u8.wrapping_sub(100), 0); assert_eq!(100u8.wrapping_sub(155), 201);

`fn wrapping_mul(self, rhs: u64) -> u64`

Wrapping (modular) multiplication. Computes `self * other`

, wrapping around at the boundary of the type.

# Examples

Basic usage:

assert_eq!(10u8.wrapping_mul(12), 120); assert_eq!(25u8.wrapping_mul(12), 44);

`fn wrapping_div(self, rhs: u64) -> u64`

Wrapping (modular) division. Computes `self / other`

.
Wrapped division on unsigned types is just normal division.
There's no way wrapping could ever happen.
This function exists, so that all operations
are accounted for in the wrapping operations.

# Examples

Basic usage:

assert_eq!(100u8.wrapping_div(10), 10);

`fn wrapping_rem(self, rhs: u64) -> u64`

Wrapping (modular) remainder. Computes `self % other`

.
Wrapped remainder calculation on unsigned types is
just the regular remainder calculation.
There's no way wrapping could ever happen.
This function exists, so that all operations
are accounted for in the wrapping operations.

# Examples

Basic usage:

assert_eq!(100i8.wrapping_rem(10), 0);

`fn wrapping_neg(self) -> u64`

Wrapping (modular) negation. Computes `-self`

,
wrapping around at the boundary of the type.

Since unsigned types do not have negative equivalents
all applications of this function will wrap (except for `-0`

).
For values smaller than the corresponding signed type's maximum
the result is the same as casting the corresponding signed value.
Any larger values are equivalent to `MAX + 1 - (val - MAX - 1)`

where
`MAX`

is the corresponding signed type's maximum.

# Examples

Basic usage:

assert_eq!(100u8.wrapping_neg(), 156); assert_eq!(0u8.wrapping_neg(), 0); assert_eq!(180u8.wrapping_neg(), 76); assert_eq!(180u8.wrapping_neg(), (127 + 1) - (180u8 - (127 + 1)));

`fn wrapping_shl(self, rhs: u32) -> u64`

Panic-free bitwise shift-left; yields `self << mask(rhs)`

,
where `mask`

removes any high-order bits of `rhs`

that
would cause the shift to exceed the bitwidth of the type.

# Examples

Basic usage:

assert_eq!(1u8.wrapping_shl(7), 128); assert_eq!(1u8.wrapping_shl(8), 1);

`fn wrapping_shr(self, rhs: u32) -> u64`

Panic-free bitwise shift-right; yields `self >> mask(rhs)`

,
where `mask`

removes any high-order bits of `rhs`

that
would cause the shift to exceed the bitwidth of the type.

# Examples

Basic usage:

assert_eq!(128u8.wrapping_shr(7), 1); assert_eq!(128u8.wrapping_shr(8), 128);

`fn overflowing_add(self, rhs: u64) -> (u64, bool)`

Calculates `self`

+ `rhs`

Returns a tuple of the addition along with a boolean indicating whether an arithmetic overflow would occur. If an overflow would have occurred then the wrapped value is returned.

# Examples

Basic usage

use std::u32; assert_eq!(5u32.overflowing_add(2), (7, false)); assert_eq!(u32::MAX.overflowing_add(1), (0, true));

`fn overflowing_sub(self, rhs: u64) -> (u64, bool)`

Calculates `self`

- `rhs`

Returns a tuple of the subtraction along with a boolean indicating whether an arithmetic overflow would occur. If an overflow would have occurred then the wrapped value is returned.

# Examples

Basic usage

use std::u32; assert_eq!(5u32.overflowing_sub(2), (3, false)); assert_eq!(0u32.overflowing_sub(1), (u32::MAX, true));

`fn overflowing_mul(self, rhs: u64) -> (u64, bool)`

Calculates the multiplication of `self`

and `rhs`

.

Returns a tuple of the multiplication along with a boolean indicating whether an arithmetic overflow would occur. If an overflow would have occurred then the wrapped value is returned.

# Examples

Basic usage

assert_eq!(5u32.overflowing_mul(2), (10, false)); assert_eq!(1_000_000_000u32.overflowing_mul(10), (1410065408, true));

`fn overflowing_div(self, rhs: u64) -> (u64, bool)`

Calculates the divisor when `self`

is divided by `rhs`

.

Returns a tuple of the divisor along with a boolean indicating
whether an arithmetic overflow would occur. Note that for unsigned
integers overflow never occurs, so the second value is always
`false`

.

# Panics

This function will panic if `rhs`

is 0.

# Examples

Basic usage

assert_eq!(5u32.overflowing_div(2), (2, false));

`fn overflowing_rem(self, rhs: u64) -> (u64, bool)`

Calculates the remainder when `self`

is divided by `rhs`

.

Returns a tuple of the remainder after dividing along with a boolean
indicating whether an arithmetic overflow would occur. Note that for
unsigned integers overflow never occurs, so the second value is
always `false`

.

# Panics

This function will panic if `rhs`

is 0.

# Examples

Basic usage

assert_eq!(5u32.overflowing_rem(2), (1, false));

`fn overflowing_neg(self) -> (u64, bool)`

Negates self in an overflowing fashion.

Returns `!self + 1`

using wrapping operations to return the value
that represents the negation of this unsigned value. Note that for
positive unsigned values overflow always occurs, but negating 0 does
not overflow.

# Examples

Basic usage

assert_eq!(0u32.overflowing_neg(), (0, false)); assert_eq!(2u32.overflowing_neg(), (-2i32 as u32, true));

`fn overflowing_shl(self, rhs: u32) -> (u64, bool)`

Shifts self left by `rhs`

bits.

Returns a tuple of the shifted version of self along with a boolean indicating whether the shift value was larger than or equal to the number of bits. If the shift value is too large, then value is masked (N-1) where N is the number of bits, and this value is then used to perform the shift.

# Examples

Basic usage

assert_eq!(0x10u32.overflowing_shl(4), (0x100, false)); assert_eq!(0x10u32.overflowing_shl(36), (0x100, true));

`fn overflowing_shr(self, rhs: u32) -> (u64, bool)`

Shifts self right by `rhs`

bits.

Returns a tuple of the shifted version of self along with a boolean indicating whether the shift value was larger than or equal to the number of bits. If the shift value is too large, then value is masked (N-1) where N is the number of bits, and this value is then used to perform the shift.

# Examples

Basic usage

assert_eq!(0x10u32.overflowing_shr(4), (0x1, false)); assert_eq!(0x10u32.overflowing_shr(36), (0x1, true));

`fn pow(self, exp: u32) -> u64`

Raises self to the power of `exp`

, using exponentiation by squaring.

# Examples

Basic usage:

assert_eq!(2u32.pow(4), 16);

`fn is_power_of_two(self) -> bool`

Returns `true`

if and only if `self == 2^k`

for some `k`

.

# Examples

Basic usage:

assert!(16u8.is_power_of_two()); assert!(!10u8.is_power_of_two());

`fn next_power_of_two(self) -> u64`

Returns the smallest power of two greater than or equal to `self`

.
Unspecified behavior on overflow.

# Examples

Basic usage:

assert_eq!(2u8.next_power_of_two(), 2); assert_eq!(3u8.next_power_of_two(), 4);

`fn checked_next_power_of_two(self) -> Option<u64>`

Returns the smallest power of two greater than or equal to `n`

. If
the next power of two is greater than the type's maximum value,
`None`

is returned, otherwise the power of two is wrapped in `Some`

.

# Examples

Basic usage:

assert_eq!(2u8.checked_next_power_of_two(), Some(2)); assert_eq!(3u8.checked_next_power_of_two(), Some(4)); assert_eq!(200u8.checked_next_power_of_two(), None);