Primitive Type u8

1.0.0 ·
Expand description

The 8-bit unsigned integer type.

Implementations§

The smallest value that can be represented by this integer type.

Examples

Basic usage:

assert_eq!(u8::MIN, 0);
Run

The largest value that can be represented by this integer type (28 − 1)

Examples

Basic usage:

assert_eq!(u8::MAX, 255);
Run

The size of this integer type in bits.

Examples
assert_eq!(u8::BITS, 8);
Run

Converts a string slice in a given base to an integer.

The string is expected to be an optional + sign followed by digits. Leading and trailing whitespace represent an error. Digits are a subset of these characters, depending on radix:

  • 0-9
  • a-z
  • A-Z
Panics

This function panics if radix is not in the range from 2 to 36.

Examples

Basic usage:

assert_eq!(u8::from_str_radix("A", 16), Ok(10));
Run

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

Examples

Basic usage:

let n = 0b01001100u8;

assert_eq!(n.count_ones(), 3);
Run

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

Examples

Basic usage:

assert_eq!(u8::MAX.count_zeros(), 0);
Run

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

Depending on what you’re doing with the value, you might also be interested in the ilog2 function which returns a consistent number, even if the type widens.

Examples

Basic usage:

let n = u8::MAX >> 2;

assert_eq!(n.leading_zeros(), 2);
Run

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

Examples

Basic usage:

let n = 0b0101000u8;

assert_eq!(n.trailing_zeros(), 3);
Run

Returns the number of leading ones in the binary representation of self.

Examples

Basic usage:

let n = !(u8::MAX >> 2);

assert_eq!(n.leading_ones(), 2);
Run

Returns the number of trailing ones in the binary representation of self.

Examples

Basic usage:

let n = 0b1010111u8;

assert_eq!(n.trailing_ones(), 3);
Run

Shifts the bits to the left by a specified amount, n, wrapping the truncated bits to the end of the resulting integer.

Please note this isn’t the same operation as the << shifting operator!

Examples

Basic usage:

let n = 0x82u8;
let m = 0xa;

assert_eq!(n.rotate_left(2), m);
Run

Shifts the bits to the right by a specified amount, n, wrapping the truncated bits to the beginning of the resulting integer.

Please note this isn’t the same operation as the >> shifting operator!

Examples

Basic usage:

let n = 0xau8;
let m = 0x82;

assert_eq!(n.rotate_right(2), m);
Run

Reverses the byte order of the integer.

Examples

Basic usage:

let n = 0x12u8;
let m = n.swap_bytes();

assert_eq!(m, 0x12);
Run

Reverses the order of bits in the integer. The least significant bit becomes the most significant bit, second least-significant bit becomes second most-significant bit, etc.

Examples

Basic usage:

let n = 0x12u8;
let m = n.reverse_bits();

assert_eq!(m, 0x48);
assert_eq!(0, 0u8.reverse_bits());
Run

Converts an integer from big endian to the target’s endianness.

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

Examples

Basic usage:

let n = 0x1Au8;

if cfg!(target_endian = "big") {
    assert_eq!(u8::from_be(n), n)
} else {
    assert_eq!(u8::from_be(n), n.swap_bytes())
}
Run

Converts an integer from little endian to the target’s endianness.

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

Examples

Basic usage:

let n = 0x1Au8;

if cfg!(target_endian = "little") {
    assert_eq!(u8::from_le(n), n)
} else {
    assert_eq!(u8::from_le(n), n.swap_bytes())
}
Run

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 = 0x1Au8;

if cfg!(target_endian = "big") {
    assert_eq!(n.to_be(), n)
} else {
    assert_eq!(n.to_be(), n.swap_bytes())
}
Run

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 = 0x1Au8;

if cfg!(target_endian = "little") {
    assert_eq!(n.to_le(), n)
} else {
    assert_eq!(n.to_le(), n.swap_bytes())
}
Run

Checked integer addition. Computes self + rhs, returning None if overflow occurred.

Examples

Basic usage:

assert_eq!((u8::MAX - 2).checked_add(1), Some(u8::MAX - 1));
assert_eq!((u8::MAX - 2).checked_add(3), None);
Run
🔬This is a nightly-only experimental API. (unchecked_math #85122)

Unchecked integer addition. Computes self + rhs, assuming overflow cannot occur.

Safety

This results in undefined behavior when self + rhs > u8::MAX or self + rhs < u8::MIN, i.e. when checked_add would return None.

Checked addition with a signed integer. Computes self + rhs, returning None if overflow occurred.

Examples

Basic usage:

assert_eq!(1u8.checked_add_signed(2), Some(3));
assert_eq!(1u8.checked_add_signed(-2), None);
assert_eq!((u8::MAX - 2).checked_add_signed(3), None);
Run

Checked integer subtraction. Computes self - rhs, returning None if overflow occurred.

Examples

Basic usage:

assert_eq!(1u8.checked_sub(1), Some(0));
assert_eq!(0u8.checked_sub(1), None);
Run
🔬This is a nightly-only experimental API. (unchecked_math #85122)

Unchecked integer subtraction. Computes self - rhs, assuming overflow cannot occur.

Safety

This results in undefined behavior when self - rhs > u8::MAX or self - rhs < u8::MIN, i.e. when checked_sub would return None.

Checked integer multiplication. Computes self * rhs, returning None if overflow occurred.

Examples

Basic usage:

assert_eq!(5u8.checked_mul(1), Some(5));
assert_eq!(u8::MAX.checked_mul(2), None);
Run
🔬This is a nightly-only experimental API. (unchecked_math #85122)

Unchecked integer multiplication. Computes self * rhs, assuming overflow cannot occur.

Safety

This results in undefined behavior when self * rhs > u8::MAX or self * rhs < u8::MIN, i.e. when checked_mul would return None.

Checked integer division. Computes self / rhs, returning None if rhs == 0.

Examples

Basic usage:

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

Checked Euclidean division. Computes self.div_euclid(rhs), returning None if rhs == 0.

Examples

Basic usage:

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

Checked integer remainder. Computes self % rhs, returning None if rhs == 0.

Examples

Basic usage:

assert_eq!(5u8.checked_rem(2), Some(1));
assert_eq!(5u8.checked_rem(0), None);
Run

Checked Euclidean modulo. Computes self.rem_euclid(rhs), returning None if rhs == 0.

Examples

Basic usage:

assert_eq!(5u8.checked_rem_euclid(2), Some(1));
assert_eq!(5u8.checked_rem_euclid(0), None);
Run

Returns the logarithm of the number with respect to an arbitrary base, rounded down.

This method might not be optimized owing to implementation details; ilog2 can produce results more efficiently for base 2, and ilog10 can produce results more efficiently for base 10.

Panics

This function will panic if self is zero, or if base is less than 2.

Examples
assert_eq!(5u8.ilog(5), 1);
Run

Returns the base 2 logarithm of the number, rounded down.

Panics

This function will panic if self is zero.

Examples
assert_eq!(2u8.ilog2(), 1);
Run

Returns the base 10 logarithm of the number, rounded down.

Panics

This function will panic if self is zero.

Example
assert_eq!(10u8.ilog10(), 1);
Run

Returns the logarithm of the number with respect to an arbitrary base, rounded down.

Returns None if the number is zero, or if the base is not at least 2.

This method might not be optimized owing to implementation details; checked_ilog2 can produce results more efficiently for base 2, and checked_ilog10 can produce results more efficiently for base 10.

Examples
assert_eq!(5u8.checked_ilog(5), Some(1));
Run

Returns the base 2 logarithm of the number, rounded down.

Returns None if the number is zero.

Examples
assert_eq!(2u8.checked_ilog2(), Some(1));
Run

Returns the base 10 logarithm of the number, rounded down.

Returns None if the number is zero.

Examples
assert_eq!(10u8.checked_ilog10(), Some(1));
Run

Checked negation. Computes -self, returning None unless self == 0.

Note that negating any positive integer will overflow.

Examples

Basic usage:

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

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!(0x1u8.checked_shl(4), Some(0x10));
assert_eq!(0x10u8.checked_shl(129), None);
Run
🔬This is a nightly-only experimental API. (unchecked_math #85122)

Unchecked shift left. Computes self << rhs, assuming that rhs is less than the number of bits in self.

Safety

This results in undefined behavior if rhs is larger than or equal to the number of bits in self, i.e. when checked_shl would return None.

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!(0x10u8.checked_shr(4), Some(0x1));
assert_eq!(0x10u8.checked_shr(129), None);
Run
🔬This is a nightly-only experimental API. (unchecked_math #85122)

Unchecked shift right. Computes self >> rhs, assuming that rhs is less than the number of bits in self.

Safety

This results in undefined behavior if rhs is larger than or equal to the number of bits in self, i.e. when checked_shr would return None.

Checked exponentiation. Computes self.pow(exp), returning None if overflow occurred.

Examples

Basic usage:

assert_eq!(2u8.checked_pow(5), Some(32));
assert_eq!(u8::MAX.checked_pow(2), None);
Run

Saturating integer addition. Computes self + rhs, saturating at the numeric bounds instead of overflowing.

Examples

Basic usage:

assert_eq!(100u8.saturating_add(1), 101);
assert_eq!(u8::MAX.saturating_add(127), u8::MAX);
Run

Saturating addition with a signed integer. Computes self + rhs, saturating at the numeric bounds instead of overflowing.

Examples

Basic usage:

assert_eq!(1u8.saturating_add_signed(2), 3);
assert_eq!(1u8.saturating_add_signed(-2), 0);
assert_eq!((u8::MAX - 2).saturating_add_signed(4), u8::MAX);
Run

Saturating integer subtraction. Computes self - rhs, 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);
Run

Saturating integer multiplication. Computes self * rhs, saturating at the numeric bounds instead of overflowing.

Examples

Basic usage:

assert_eq!(2u8.saturating_mul(10), 20);
assert_eq!((u8::MAX).saturating_mul(10), u8::MAX);
Run

Saturating integer division. Computes self / rhs, saturating at the numeric bounds instead of overflowing.

Examples

Basic usage:

assert_eq!(5u8.saturating_div(2), 2);
Run
ⓘ
let _ = 1u8.saturating_div(0);
Run

Saturating integer exponentiation. Computes self.pow(exp), saturating at the numeric bounds instead of overflowing.

Examples

Basic usage:

assert_eq!(4u8.saturating_pow(3), 64);
assert_eq!(u8::MAX.saturating_pow(2), u8::MAX);
Run

Wrapping (modular) addition. Computes self + rhs, wrapping around at the boundary of the type.

Examples

Basic usage:

assert_eq!(200u8.wrapping_add(55), 255);
assert_eq!(200u8.wrapping_add(u8::MAX), 199);
Run

Wrapping (modular) addition with a signed integer. Computes self + rhs, wrapping around at the boundary of the type.

Examples

Basic usage:

assert_eq!(1u8.wrapping_add_signed(2), 3);
assert_eq!(1u8.wrapping_add_signed(-2), u8::MAX);
assert_eq!((u8::MAX - 2).wrapping_add_signed(4), 1);
Run

Wrapping (modular) subtraction. Computes self - rhs, wrapping around at the boundary of the type.

Examples

Basic usage:

assert_eq!(100u8.wrapping_sub(100), 0);
assert_eq!(100u8.wrapping_sub(u8::MAX), 101);
Run

Wrapping (modular) multiplication. Computes self * rhs, wrapping around at the boundary of the type.

Examples

Basic usage:

Please note that this example is shared between integer types. Which explains why u8 is used here.

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

Wrapping (modular) division. Computes self / rhs. 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);
Run

Wrapping Euclidean division. Computes self.div_euclid(rhs). 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. Since, for the positive integers, all common definitions of division are equal, this is exactly equal to self.wrapping_div(rhs).

Examples

Basic usage:

assert_eq!(100u8.wrapping_div_euclid(10), 10);
Run

Wrapping (modular) remainder. Computes self % rhs. 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!(100u8.wrapping_rem(10), 0);
Run

Wrapping Euclidean modulo. Computes self.rem_euclid(rhs). Wrapped modulo 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. Since, for the positive integers, all common definitions of division are equal, this is exactly equal to self.wrapping_rem(rhs).

Examples

Basic usage:

assert_eq!(100u8.wrapping_rem_euclid(10), 0);
Run

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:

Please note that this example is shared between integer types. Which explains why i8 is used here.

assert_eq!(100i8.wrapping_neg(), -100);
assert_eq!((-128i8).wrapping_neg(), -128);
Run

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.

Note that this is not the same as a rotate-left; the RHS of a wrapping shift-left is restricted to the range of the type, rather than the bits shifted out of the LHS being returned to the other end. The primitive integer types all implement a rotate_left function, which may be what you want instead.

Examples

Basic usage:

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

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.

Note that this is not the same as a rotate-right; the RHS of a wrapping shift-right is restricted to the range of the type, rather than the bits shifted out of the LHS being returned to the other end. The primitive integer types all implement a rotate_right function, which may be what you want instead.

Examples

Basic usage:

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

Wrapping (modular) exponentiation. Computes self.pow(exp), wrapping around at the boundary of the type.

Examples

Basic usage:

assert_eq!(3u8.wrapping_pow(5), 243);
assert_eq!(3u8.wrapping_pow(6), 217);
Run

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

assert_eq!(5u8.overflowing_add(2), (7, false));
assert_eq!(u8::MAX.overflowing_add(1), (0, true));
Run
🔬This is a nightly-only experimental API. (bigint_helper_methods #85532)

Calculates self + rhs + carry and returns a tuple containing the sum and the output carry.

Performs “ternary addition” of two integer operands and a carry-in bit, and returns an output integer and a carry-out bit. This allows chaining together multiple additions to create a wider addition, and can be useful for bignum addition.

This can be thought of as a 8-bit “full adder”, in the electronics sense.

If the input carry is false, this method is equivalent to overflowing_add, and the output carry is equal to the overflow flag. Note that although carry and overflow flags are similar for unsigned integers, they are different for signed integers.

Examples
#![feature(bigint_helper_methods)]

//    3  MAX    (a = 3 × 2^8 + 2^8 - 1)
// +  5    7    (b = 5 × 2^8 + 7)
// ---------
//    9    6    (sum = 9 × 2^8 + 6)

let (a1, a0): (u8, u8) = (3, u8::MAX);
let (b1, b0): (u8, u8) = (5, 7);
let carry0 = false;

let (sum0, carry1) = a0.carrying_add(b0, carry0);
assert_eq!(carry1, true);
let (sum1, carry2) = a1.carrying_add(b1, carry1);
assert_eq!(carry2, false);

assert_eq!((sum1, sum0), (9, 6));
Run

Calculates self + rhs with a signed 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:

assert_eq!(1u8.overflowing_add_signed(2), (3, false));
assert_eq!(1u8.overflowing_add_signed(-2), (u8::MAX, true));
assert_eq!((u8::MAX - 2).overflowing_add_signed(4), (1, true));
Run

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

assert_eq!(5u8.overflowing_sub(2), (3, false));
assert_eq!(0u8.overflowing_sub(1), (u8::MAX, true));
Run
🔬This is a nightly-only experimental API. (bigint_helper_methods #85532)

Calculates self − rhs − borrow and returns a tuple containing the difference and the output borrow.

Performs “ternary subtraction” by subtracting both an integer operand and a borrow-in bit from self, and returns an output integer and a borrow-out bit. This allows chaining together multiple subtractions to create a wider subtraction, and can be useful for bignum subtraction.

Examples
#![feature(bigint_helper_methods)]

//    9    6    (a = 9 × 2^8 + 6)
// -  5    7    (b = 5 × 2^8 + 7)
// ---------
//    3  MAX    (diff = 3 × 2^8 + 2^8 - 1)

let (a1, a0): (u8, u8) = (9, 6);
let (b1, b0): (u8, u8) = (5, 7);
let borrow0 = false;

let (diff0, borrow1) = a0.borrowing_sub(b0, borrow0);
assert_eq!(borrow1, true);
let (diff1, borrow2) = a1.borrowing_sub(b1, borrow1);
assert_eq!(borrow2, false);

assert_eq!((diff1, diff0), (3, u8::MAX));
Run

Computes the absolute difference between self and other.

Examples

Basic usage:

assert_eq!(100u8.abs_diff(80), 20u8);
assert_eq!(100u8.abs_diff(110), 10u8);
Run

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:

Please note that this example is shared between integer types. Which explains why u32 is used here.

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

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!(5u8.overflowing_div(2), (2, false));
Run

Calculates the quotient of Euclidean division self.div_euclid(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. Since, for the positive integers, all common definitions of division are equal, this is exactly equal to self.overflowing_div(rhs).

Panics

This function will panic if rhs is 0.

Examples

Basic usage

assert_eq!(5u8.overflowing_div_euclid(2), (2, false));
Run

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!(5u8.overflowing_rem(2), (1, false));
Run

Calculates the remainder self.rem_euclid(rhs) as if by Euclidean division.

Returns a tuple of the modulo 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. Since, for the positive integers, all common definitions of division are equal, this operation is exactly equal to self.overflowing_rem(rhs).

Panics

This function will panic if rhs is 0.

Examples

Basic usage

assert_eq!(5u8.overflowing_rem_euclid(2), (1, false));
Run

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!(0u8.overflowing_neg(), (0, false));
assert_eq!(2u8.overflowing_neg(), (-2i32 as u8, true));
Run

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!(0x1u8.overflowing_shl(4), (0x10, false));
assert_eq!(0x1u8.overflowing_shl(132), (0x10, true));
Run

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!(0x10u8.overflowing_shr(4), (0x1, false));
assert_eq!(0x10u8.overflowing_shr(132), (0x1, true));
Run

Raises self to the power of exp, using exponentiation by squaring.

Returns a tuple of the exponentiation along with a bool indicating whether an overflow happened.

Examples

Basic usage:

assert_eq!(3u8.overflowing_pow(5), (243, false));
assert_eq!(3u8.overflowing_pow(6), (217, true));
Run

Raises self to the power of exp, using exponentiation by squaring.

Examples

Basic usage:

assert_eq!(2u8.pow(5), 32);
Run

Performs Euclidean division.

Since, for the positive integers, all common definitions of division are equal, this is exactly equal to self / rhs.

Panics

This function will panic if rhs is 0.

Examples

Basic usage:

assert_eq!(7u8.div_euclid(4), 1); // or any other integer type
Run

Calculates the least remainder of self (mod rhs).

Since, for the positive integers, all common definitions of division are equal, this is exactly equal to self % rhs.

Panics

This function will panic if rhs is 0.

Examples

Basic usage:

assert_eq!(7u8.rem_euclid(4), 3); // or any other integer type
Run
🔬This is a nightly-only experimental API. (int_roundings #88581)

Calculates the quotient of self and rhs, rounding the result towards negative infinity.

This is the same as performing self / rhs for all unsigned integers.

Panics

This function will panic if rhs is zero.

Examples

Basic usage:

#![feature(int_roundings)]
assert_eq!(7_u8.div_floor(4), 1);
Run
🔬This is a nightly-only experimental API. (int_roundings #88581)

Calculates the quotient of self and rhs, rounding the result towards positive infinity.

Panics

This function will panic if rhs is zero.

Overflow behavior

On overflow, this function will panic if overflow checks are enabled (default in debug mode) and wrap if overflow checks are disabled (default in release mode).

Examples

Basic usage:

#![feature(int_roundings)]
assert_eq!(7_u8.div_ceil(4), 2);
Run
🔬This is a nightly-only experimental API. (int_roundings #88581)

Calculates the smallest value greater than or equal to self that is a multiple of rhs.

Panics

This function will panic if rhs is zero.

Overflow behavior

On overflow, this function will panic if overflow checks are enabled (default in debug mode) and wrap if overflow checks are disabled (default in release mode).

Examples

Basic usage:

#![feature(int_roundings)]
assert_eq!(16_u8.next_multiple_of(8), 16);
assert_eq!(23_u8.next_multiple_of(8), 24);
Run
🔬This is a nightly-only experimental API. (int_roundings #88581)

Calculates the smallest value greater than or equal to self that is a multiple of rhs. Returns None if rhs is zero or the operation would result in overflow.

Examples

Basic usage:

#![feature(int_roundings)]
assert_eq!(16_u8.checked_next_multiple_of(8), Some(16));
assert_eq!(23_u8.checked_next_multiple_of(8), Some(24));
assert_eq!(1_u8.checked_next_multiple_of(0), None);
assert_eq!(u8::MAX.checked_next_multiple_of(2), None);
Run

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());
Run

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

When return value overflows (i.e., self > (1 << (N-1)) for type uN), it panics in debug mode and the return value is wrapped to 0 in release mode (the only situation in which method can return 0).

Examples

Basic usage:

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

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!(u8::MAX.checked_next_power_of_two(), None);
Run
🔬This is a nightly-only experimental API. (wrapping_next_power_of_two #32463)

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, the return value is wrapped to 0.

Examples

Basic usage:

#![feature(wrapping_next_power_of_two)]

assert_eq!(2u8.wrapping_next_power_of_two(), 2);
assert_eq!(3u8.wrapping_next_power_of_two(), 4);
assert_eq!(u8::MAX.wrapping_next_power_of_two(), 0);
Run

Return the memory representation of this integer as a byte array in big-endian (network) byte order.

Examples
let bytes = 0x12u8.to_be_bytes();
assert_eq!(bytes, [0x12]);
Run

Return the memory representation of this integer as a byte array in little-endian byte order.

Examples
let bytes = 0x12u8.to_le_bytes();
assert_eq!(bytes, [0x12]);
Run

Return the memory representation of this integer as a byte array in native byte order.

As the target platform’s native endianness is used, portable code should use to_be_bytes or to_le_bytes, as appropriate, instead.

Examples
let bytes = 0x12u8.to_ne_bytes();
assert_eq!(
    bytes,
    if cfg!(target_endian = "big") {
        [0x12]
    } else {
        [0x12]
    }
);
Run

Create a native endian integer value from its representation as a byte array in big endian.

Examples
let value = u8::from_be_bytes([0x12]);
assert_eq!(value, 0x12);
Run

When starting from a slice rather than an array, fallible conversion APIs can be used:

fn read_be_u8(input: &mut &[u8]) -> u8 {
    let (int_bytes, rest) = input.split_at(std::mem::size_of::<u8>());
    *input = rest;
    u8::from_be_bytes(int_bytes.try_into().unwrap())
}
Run

Create a native endian integer value from its representation as a byte array in little endian.

Examples
let value = u8::from_le_bytes([0x12]);
assert_eq!(value, 0x12);
Run

When starting from a slice rather than an array, fallible conversion APIs can be used:

fn read_le_u8(input: &mut &[u8]) -> u8 {
    let (int_bytes, rest) = input.split_at(std::mem::size_of::<u8>());
    *input = rest;
    u8::from_le_bytes(int_bytes.try_into().unwrap())
}
Run

Create a native endian integer value from its memory representation as a byte array in native endianness.

As the target platform’s native endianness is used, portable code likely wants to use from_be_bytes or from_le_bytes, as appropriate instead.

Examples
let value = u8::from_ne_bytes(if cfg!(target_endian = "big") {
    [0x12]
} else {
    [0x12]
});
assert_eq!(value, 0x12);
Run

When starting from a slice rather than an array, fallible conversion APIs can be used:

fn read_ne_u8(input: &mut &[u8]) -> u8 {
    let (int_bytes, rest) = input.split_at(std::mem::size_of::<u8>());
    *input = rest;
    u8::from_ne_bytes(int_bytes.try_into().unwrap())
}
Run
👎Deprecating in a future Rust version: replaced by the MIN associated constant on this type

New code should prefer to use u8::MIN instead.

Returns the smallest value that can be represented by this integer type.

👎Deprecating in a future Rust version: replaced by the MAX associated constant on this type

New code should prefer to use u8::MAX instead.

Returns the largest value that can be represented by this integer type.

🔬This is a nightly-only experimental API. (bigint_helper_methods #85532)

Calculates the complete product self * rhs without the possibility to overflow.

This returns the low-order (wrapping) bits and the high-order (overflow) bits of the result as two separate values, in that order.

If you also need to add a carry to the wide result, then you want Self::carrying_mul instead.

Examples

Basic usage:

Please note that this example is shared between integer types. Which explains why u32 is used here.

#![feature(bigint_helper_methods)]
assert_eq!(5u32.widening_mul(2), (10, 0));
assert_eq!(1_000_000_000u32.widening_mul(10), (1410065408, 2));
Run
🔬This is a nightly-only experimental API. (bigint_helper_methods #85532)

Calculates the “full multiplication” self * rhs + carry without the possibility to overflow.

This returns the low-order (wrapping) bits and the high-order (overflow) bits of the result as two separate values, in that order.

Performs “long multiplication” which takes in an extra amount to add, and may return an additional amount of overflow. This allows for chaining together multiple multiplications to create “big integers” which represent larger values.

If you don’t need the carry, then you can use Self::widening_mul instead.

Examples

Basic usage:

Please note that this example is shared between integer types. Which explains why u32 is used here.

#![feature(bigint_helper_methods)]
assert_eq!(5u32.carrying_mul(2, 0), (10, 0));
assert_eq!(5u32.carrying_mul(2, 10), (20, 0));
assert_eq!(1_000_000_000u32.carrying_mul(10, 0), (1410065408, 2));
assert_eq!(1_000_000_000u32.carrying_mul(10, 10), (1410065418, 2));
assert_eq!(u8::MAX.carrying_mul(u8::MAX, u8::MAX), (0, u8::MAX));
Run

This is the core operation needed for scalar multiplication when implementing it for wider-than-native types.

#![feature(bigint_helper_methods)]
fn scalar_mul_eq(little_endian_digits: &mut Vec<u16>, multiplicand: u16) {
    let mut carry = 0;
    for d in little_endian_digits.iter_mut() {
        (*d, carry) = d.carrying_mul(multiplicand, carry);
    }
    if carry != 0 {
        little_endian_digits.push(carry);
    }
}

let mut v = vec![10, 20];
scalar_mul_eq(&mut v, 3);
assert_eq!(v, [30, 60]);

assert_eq!(0x87654321_u64 * 0xFEED, 0x86D3D159E38D);
let mut v = vec![0x4321, 0x8765];
scalar_mul_eq(&mut v, 0xFEED);
assert_eq!(v, [0xE38D, 0xD159, 0x86D3]);
Run

If carry is zero, this is similar to overflowing_mul, except that it gives the value of the overflow instead of just whether one happened:

#![feature(bigint_helper_methods)]
let r = u8::carrying_mul(7, 13, 0);
assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(7, 13));
let r = u8::carrying_mul(13, 42, 0);
assert_eq!((r.0, r.1 != 0), u8::overflowing_mul(13, 42));
Run

The value of the first field in the returned tuple matches what you’d get by combining the wrapping_mul and wrapping_add methods:

#![feature(bigint_helper_methods)]
assert_eq!(
    789_u16.carrying_mul(456, 123).0,
    789_u16.wrapping_mul(456).wrapping_add(123),
);
Run

Checks if the value is within the ASCII range.

Examples
let ascii = 97u8;
let non_ascii = 150u8;

assert!(ascii.is_ascii());
assert!(!non_ascii.is_ascii());
Run

Makes a copy of the value in its ASCII upper case equivalent.

ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.

To uppercase the value in-place, use make_ascii_uppercase.

Examples
let lowercase_a = 97u8;

assert_eq!(65, lowercase_a.to_ascii_uppercase());
Run

Makes a copy of the value in its ASCII lower case equivalent.

ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.

To lowercase the value in-place, use make_ascii_lowercase.

Examples
let uppercase_a = 65u8;

assert_eq!(97, uppercase_a.to_ascii_lowercase());
Run

Checks that two values are an ASCII case-insensitive match.

This is equivalent to to_ascii_lowercase(a) == to_ascii_lowercase(b).

Examples
let lowercase_a = 97u8;
let uppercase_a = 65u8;

assert!(lowercase_a.eq_ignore_ascii_case(&uppercase_a));
Run

Converts this value to its ASCII upper case equivalent in-place.

ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.

To return a new uppercased value without modifying the existing one, use to_ascii_uppercase.

Examples
let mut byte = b'a';

byte.make_ascii_uppercase();

assert_eq!(b'A', byte);
Run

Converts this value to its ASCII lower case equivalent in-place.

ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.

To return a new lowercased value without modifying the existing one, use to_ascii_lowercase.

Examples
let mut byte = b'A';

byte.make_ascii_lowercase();

assert_eq!(b'a', byte);
Run

Checks if the value is an ASCII alphabetic character:

  • U+0041 ‘A’ ..= U+005A ‘Z’, or
  • U+0061 ‘a’ ..= U+007A ‘z’.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';

assert!(uppercase_a.is_ascii_alphabetic());
assert!(uppercase_g.is_ascii_alphabetic());
assert!(a.is_ascii_alphabetic());
assert!(g.is_ascii_alphabetic());
assert!(!zero.is_ascii_alphabetic());
assert!(!percent.is_ascii_alphabetic());
assert!(!space.is_ascii_alphabetic());
assert!(!lf.is_ascii_alphabetic());
assert!(!esc.is_ascii_alphabetic());
Run

Checks if the value is an ASCII uppercase character: U+0041 ‘A’ ..= U+005A ‘Z’.

Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';

assert!(uppercase_a.is_ascii_uppercase());
assert!(uppercase_g.is_ascii_uppercase());
assert!(!a.is_ascii_uppercase());
assert!(!g.is_ascii_uppercase());
assert!(!zero.is_ascii_uppercase());
assert!(!percent.is_ascii_uppercase());
assert!(!space.is_ascii_uppercase());
assert!(!lf.is_ascii_uppercase());
assert!(!esc.is_ascii_uppercase());
Run

Checks if the value is an ASCII lowercase character: U+0061 ‘a’ ..= U+007A ‘z’.

Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';

assert!(!uppercase_a.is_ascii_lowercase());
assert!(!uppercase_g.is_ascii_lowercase());
assert!(a.is_ascii_lowercase());
assert!(g.is_ascii_lowercase());
assert!(!zero.is_ascii_lowercase());
assert!(!percent.is_ascii_lowercase());
assert!(!space.is_ascii_lowercase());
assert!(!lf.is_ascii_lowercase());
assert!(!esc.is_ascii_lowercase());
Run

Checks if the value is an ASCII alphanumeric character:

  • U+0041 ‘A’ ..= U+005A ‘Z’, or
  • U+0061 ‘a’ ..= U+007A ‘z’, or
  • U+0030 ‘0’ ..= U+0039 ‘9’.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';

assert!(uppercase_a.is_ascii_alphanumeric());
assert!(uppercase_g.is_ascii_alphanumeric());
assert!(a.is_ascii_alphanumeric());
assert!(g.is_ascii_alphanumeric());
assert!(zero.is_ascii_alphanumeric());
assert!(!percent.is_ascii_alphanumeric());
assert!(!space.is_ascii_alphanumeric());
assert!(!lf.is_ascii_alphanumeric());
assert!(!esc.is_ascii_alphanumeric());
Run

Checks if the value is an ASCII decimal digit: U+0030 ‘0’ ..= U+0039 ‘9’.

Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';

assert!(!uppercase_a.is_ascii_digit());
assert!(!uppercase_g.is_ascii_digit());
assert!(!a.is_ascii_digit());
assert!(!g.is_ascii_digit());
assert!(zero.is_ascii_digit());
assert!(!percent.is_ascii_digit());
assert!(!space.is_ascii_digit());
assert!(!lf.is_ascii_digit());
assert!(!esc.is_ascii_digit());
Run
🔬This is a nightly-only experimental API. (is_ascii_octdigit #101288)

Checks if the value is an ASCII octal digit: U+0030 ‘0’ ..= U+0037 ‘7’.

Examples
#![feature(is_ascii_octdigit)]

let uppercase_a = b'A';
let a = b'a';
let zero = b'0';
let seven = b'7';
let nine = b'9';
let percent = b'%';
let lf = b'\n';

assert!(!uppercase_a.is_ascii_octdigit());
assert!(!a.is_ascii_octdigit());
assert!(zero.is_ascii_octdigit());
assert!(seven.is_ascii_octdigit());
assert!(!nine.is_ascii_octdigit());
assert!(!percent.is_ascii_octdigit());
assert!(!lf.is_ascii_octdigit());
Run

Checks if the value is an ASCII hexadecimal digit:

  • U+0030 ‘0’ ..= U+0039 ‘9’, or
  • U+0041 ‘A’ ..= U+0046 ‘F’, or
  • U+0061 ‘a’ ..= U+0066 ‘f’.
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';

assert!(uppercase_a.is_ascii_hexdigit());
assert!(!uppercase_g.is_ascii_hexdigit());
assert!(a.is_ascii_hexdigit());
assert!(!g.is_ascii_hexdigit());
assert!(zero.is_ascii_hexdigit());
assert!(!percent.is_ascii_hexdigit());
assert!(!space.is_ascii_hexdigit());
assert!(!lf.is_ascii_hexdigit());
assert!(!esc.is_ascii_hexdigit());
Run

Checks if the value is an ASCII punctuation character:

  • U+0021 ..= U+002F ! " # $ % & ' ( ) * + , - . /, or
  • U+003A ..= U+0040 : ; < = > ? @, or
  • U+005B ..= U+0060 [ \ ] ^ _ `, or
  • U+007B ..= U+007E { | } ~
Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';

assert!(!uppercase_a.is_ascii_punctuation());
assert!(!uppercase_g.is_ascii_punctuation());
assert!(!a.is_ascii_punctuation());
assert!(!g.is_ascii_punctuation());
assert!(!zero.is_ascii_punctuation());
assert!(percent.is_ascii_punctuation());
assert!(!space.is_ascii_punctuation());
assert!(!lf.is_ascii_punctuation());
assert!(!esc.is_ascii_punctuation());
Run

Checks if the value is an ASCII graphic character: U+0021 ‘!’ ..= U+007E ‘~’.

Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';

assert!(uppercase_a.is_ascii_graphic());
assert!(uppercase_g.is_ascii_graphic());
assert!(a.is_ascii_graphic());
assert!(g.is_ascii_graphic());
assert!(zero.is_ascii_graphic());
assert!(percent.is_ascii_graphic());
assert!(!space.is_ascii_graphic());
assert!(!lf.is_ascii_graphic());
assert!(!esc.is_ascii_graphic());
Run

Checks if the value is an ASCII whitespace character: U+0020 SPACE, U+0009 HORIZONTAL TAB, U+000A LINE FEED, U+000C FORM FEED, or U+000D CARRIAGE RETURN.

Rust uses the WhatWG Infra Standard’s definition of ASCII whitespace. There are several other definitions in wide use. For instance, the POSIX locale includes U+000B VERTICAL TAB as well as all the above characters, but—from the very same specification—the default rule for “field splitting” in the Bourne shell considers only SPACE, HORIZONTAL TAB, and LINE FEED as whitespace.

If you are writing a program that will process an existing file format, check what that format’s definition of whitespace is before using this function.

Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';

assert!(!uppercase_a.is_ascii_whitespace());
assert!(!uppercase_g.is_ascii_whitespace());
assert!(!a.is_ascii_whitespace());
assert!(!g.is_ascii_whitespace());
assert!(!zero.is_ascii_whitespace());
assert!(!percent.is_ascii_whitespace());
assert!(space.is_ascii_whitespace());
assert!(lf.is_ascii_whitespace());
assert!(!esc.is_ascii_whitespace());
Run

Checks if the value is an ASCII control character: U+0000 NUL ..= U+001F UNIT SEPARATOR, or U+007F DELETE. Note that most ASCII whitespace characters are control characters, but SPACE is not.

Examples
let uppercase_a = b'A';
let uppercase_g = b'G';
let a = b'a';
let g = b'g';
let zero = b'0';
let percent = b'%';
let space = b' ';
let lf = b'\n';
let esc = b'\x1b';

assert!(!uppercase_a.is_ascii_control());
assert!(!uppercase_g.is_ascii_control());
assert!(!a.is_ascii_control());
assert!(!g.is_ascii_control());
assert!(!zero.is_ascii_control());
assert!(!percent.is_ascii_control());
assert!(!space.is_ascii_control());
assert!(lf.is_ascii_control());
assert!(esc.is_ascii_control());
Run

Returns an iterator that produces an escaped version of a u8, treating it as an ASCII character.

The behavior is identical to ascii::escape_default.

Examples

assert_eq!("0", b'0'.escape_ascii().to_string());
assert_eq!("\\t", b'\t'.escape_ascii().to_string());
assert_eq!("\\r", b'\r'.escape_ascii().to_string());
assert_eq!("\\n", b'\n'.escape_ascii().to_string());
assert_eq!("\\'", b'\''.escape_ascii().to_string());
assert_eq!("\\\"", b'"'.escape_ascii().to_string());
assert_eq!("\\\\", b'\\'.escape_ascii().to_string());
assert_eq!("\\x9d", b'\x9d'.escape_ascii().to_string());
Run

Trait Implementations§

The resulting type after applying the + operator.
Performs the + operation. Read more
The resulting type after applying the + operator.
Performs the + operation. Read more
The resulting type after applying the + operator.
Performs the + operation. Read more
The resulting type after applying the + operator.
Performs the + operation. Read more
Performs the += operation. Read more
Performs the += operation. Read more
Performs the += operation. Read more
Performs the += operation. Read more
Performs the += operation. Read more
Performs the += operation. Read more
👎Deprecated since 1.26.0: use inherent methods instead
Container type for copied ASCII characters.
👎Deprecated since 1.26.0: use inherent methods instead
Checks if the value is within the ASCII range. Read more
👎Deprecated since 1.26.0: use inherent methods instead
Makes a copy of the value in its ASCII upper case equivalent. Read more
👎Deprecated since 1.26.0: use inherent methods instead
Makes a copy of the value in its ASCII lower case equivalent. Read more
👎Deprecated since 1.26.0: use inherent methods instead
Checks that two values are an ASCII case-insensitive match. Read more
👎Deprecated since 1.26.0: use inherent methods instead
Converts this type to its ASCII upper case equivalent in-place. Read more
👎Deprecated since 1.26.0: use inherent methods instead
Converts this type to its ASCII lower case equivalent in-place. Read more
Formats the value using the given formatter.
The resulting type after applying the & operator.
Performs the & operation. Read more
The resulting type after applying the & operator.
Performs the & operation. Read more
The resulting type after applying the & operator.
Performs the & operation. Read more
The resulting type after applying the & operator.
Performs the & operation. Read more
Performs the &= operation. Read more
Performs the &= operation. Read more
Performs the &= operation. Read more
Performs the &= operation. Read more
Performs the &= operation. Read more
Performs the &= operation. Read more
The resulting type after applying the | operator.
Performs the | operation. Read more
The resulting type after applying the | operator.
Performs the | operation. Read more
The resulting type after applying the | operator.
Performs the | operation. Read more
The resulting type after applying the | operator.
Performs the | operation. Read more
The resulting type after applying the | operator.
Performs the | operation. Read more
The resulting type after applying the | operator.
Performs the | operation. Read more
Performs the |= operation. Read more
Performs the |= operation. Read more
Performs the |= operation. Read more
Performs the |= operation. Read more
Performs the |= operation. Read more
Performs the |= operation. Read more
Performs the |= operation. Read more
The resulting type after applying the ^ operator.
Performs the ^ operation. Read more
The resulting type after applying the ^ operator.
Performs the ^ operation. Read more
The resulting type after applying the ^ operator.
Performs the ^ operation. Read more
The resulting type after applying the ^ operator.
Performs the ^ operation. Read more
Performs the ^= operation. Read more
Performs the ^= operation. Read more
Performs the ^= operation. Read more
Performs the ^= operation. Read more
Performs the ^= operation. Read more
Performs the ^= operation. Read more
Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more

Returns the default value of 0

Formats the value using the given formatter. Read more
The resulting type after applying the / operator.
Performs the / operation. Read more
The resulting type after applying the / operator.
Performs the / operation. Read more

This operation rounds towards zero, truncating any fractional part of the exact result, and cannot panic.

The resulting type after applying the / operator.
The resulting type after applying the / operator.
Performs the / operation. Read more

This operation rounds towards zero, truncating any fractional part of the exact result.

Panics

This operation will panic if other == 0.

The resulting type after applying the / operator.
Performs the / operation. Read more
Performs the /= operation. Read more
Performs the /= operation. Read more
Performs the /= operation. Read more
Performs the /= operation. Read more
Performs the /= operation. Read more
Performs the /= operation. Read more

Converts a NonZeroU8 into an u8

Converts a bool to a u8. The resulting value is 0 for false and 1 for true values.

Examples
assert_eq!(u8::from(true), 1);
assert_eq!(u8::from(false), 0);
Run

Converts an u8 into an AtomicU8.

Construct an ExitCode from an arbitrary u8 value.

Maps a byte in 0x00..=0xFF to a char whose code point has the same value, in U+0000..=U+00FF.

Unicode is designed such that this effectively decodes bytes with the character encoding that IANA calls ISO-8859-1. This encoding is compatible with ASCII.

Note that this is different from ISO/IEC 8859-1 a.k.a. ISO 8859-1 (with one less hyphen), which leaves some “blanks”, byte values that are not assigned to any character. ISO-8859-1 (the IANA one) assigns them to the C0 and C1 control codes.

Note that this is also different from Windows-1252 a.k.a. code page 1252, which is a superset ISO/IEC 8859-1 that assigns some (not all!) blanks to punctuation and various Latin characters.

To confuse things further, on the Web ascii, iso-8859-1, and windows-1252 are all aliases for a superset of Windows-1252 that fills the remaining blanks with corresponding C0 and C1 control codes.

Converts a u8 into a char.

Examples
use std::mem;

let u = 32 as u8;
let c = char::from(u);
assert!(4 == mem::size_of_val(&c))
Run

Converts u8 to f32 losslessly.

Converts u8 to f64 losslessly.

Converts u8 to i128 losslessly.

Converts u8 to i16 losslessly.

Converts u8 to i32 losslessly.

Converts u8 to i64 losslessly.

Converts u8 to isize losslessly.

Converts u8 to u128 losslessly.

Converts u8 to u16 losslessly.

Converts u8 to u32 losslessly.

Converts u8 to u64 losslessly.

Converts u8 to usize losslessly.

The associated error which can be returned from parsing.
Parses a string s to return a value of this type. Read more
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more
Formats the value using the given formatter.
Formats the value using the given formatter.
The resulting type after applying the * operator.
Performs the * operation. Read more
The resulting type after applying the * operator.
Performs the * operation. Read more
The resulting type after applying the * operator.
Performs the * operation. Read more
The resulting type after applying the * operator.
Performs the * operation. Read more
Performs the *= operation. Read more
Performs the *= operation. Read more
Performs the *= operation. Read more
Performs the *= operation. Read more
Performs the *= operation. Read more
Performs the *= operation. Read more
The resulting type after applying the ! operator.
Performs the unary ! operation. Read more
The resulting type after applying the ! operator.
Performs the unary ! operation. Read more
Formats the value using the given formatter.
This method returns an Ordering between self and other. Read more
Compares and returns the maximum of two values. Read more
Compares and returns the minimum of two values. Read more
Restrict a value to a certain interval. Read more
This method tests for self and other values to be equal, and is used by ==. Read more
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more
This method returns an ordering between self and other values if one exists. Read more
This method tests less than (for self and other) and is used by the < operator. Read more
This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
This method tests greater than (for self and other) and is used by the > operator. Read more
Method which takes an iterator and generates Self from the elements by multiplying the items. Read more
Method which takes an iterator and generates Self from the elements by multiplying the items. Read more
The resulting type after applying the % operator.
Performs the % operation. Read more
The resulting type after applying the % operator.
Performs the % operation. Read more

This operation satisfies n % d == n - (n / d) * d, and cannot panic.

The resulting type after applying the % operator.
The resulting type after applying the % operator.
Performs the % operation. Read more

This operation satisfies n % d == n - (n / d) * d. The result has the same sign as the left operand.

Panics

This operation will panic if other == 0.

The resulting type after applying the % operator.
Performs the % operation. Read more
Performs the %= operation. Read more
Performs the %= operation. Read more
Performs the %= operation. Read more
Performs the %= operation. Read more
Performs the %= operation. Read more
Performs the %= operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
The resulting type after applying the << operator.
Performs the << operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
Performs the <<= operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
The resulting type after applying the >> operator.
Performs the >> operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
Performs the >>= operation. Read more
🔬This is a nightly-only experimental API. (portable_simd #86656)
The mask element type corresponding to this element type.
🔬This is a nightly-only experimental API. (step_trait #42168)
Returns the value that would be obtained by taking the successor of self count times. Read more
🔬This is a nightly-only experimental API. (step_trait #42168)
Returns the value that would be obtained by taking the predecessor of self count times. Read more
🔬This is a nightly-only experimental API. (step_trait #42168)
Returns the value that would be obtained by taking the successor of self count times. Read more
🔬This is a nightly-only experimental API. (step_trait #42168)
Returns the value that would be obtained by taking the predecessor of self count times. Read more
🔬This is a nightly-only experimental API. (step_trait #42168)
Returns the number of successor steps required to get from start to end. Read more
🔬This is a nightly-only experimental API. (step_trait #42168)
Returns the value that would be obtained by taking the successor of self count times. Read more
🔬This is a nightly-only experimental API. (step_trait #42168)
Returns the value that would be obtained by taking the predecessor of self count times. Read more
The resulting type after applying the - operator.
Performs the - operation. Read more
The resulting type after applying the - operator.
Performs the - operation. Read more
The resulting type after applying the - operator.
Performs the - operation. Read more
The resulting type after applying the - operator.
Performs the - operation. Read more
Performs the -= operation. Read more
Performs the -= operation. Read more
Performs the -= operation. Read more
Performs the -= operation. Read more
Performs the -= operation. Read more
Performs the -= operation. Read more
Method which takes an iterator and generates Self from the elements by “summing up” the items. Read more
Method which takes an iterator and generates Self from the elements by “summing up” the items. Read more
Converts the given value to a String. Read more

Map char with code point in U+0000..=U+00FF to byte in 0x00..=0xFF with same value, failing if the code point is greater than U+00FF.

See impl From<u8> for char for details on the encoding.

The type returned in the event of a conversion error.
Performs the conversion.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Attempts to convert u8 to NonZeroU8.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

The type returned in the event of a conversion error.
Formats the value using the given formatter.
Formats the value using the given formatter.

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
Converts the given value to a String. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.