Primitive Type isize1.0.0[−]

Expand description

The pointer-sized signed integer type.

The size of this primitive is how many bytes it takes to reference any location in memory. For example, on a 32 bit target, this is 4 bytes and on a 64 bit target, this is 8 bytes.

Implementations

The smallest value that can be represented by this integer type, -263.

Examples

Basic usage:

assert_eq!(isize::MIN, -9223372036854775808);
Run

The largest value that can be represented by this integer type, 263 - 1.

Examples

Basic usage:

assert_eq!(isize::MAX, 9223372036854775807);
Run

The size of this integer type in bits.

Examples

assert_eq!(isize::BITS, 64);
Run

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

The string is expected to be an optional + or - 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!(isize::from_str_radix("A", 16), Ok(10));
Run

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

Examples

Basic usage:

let n = 0b100_0000isize;

assert_eq!(n.count_ones(), 1);
Run

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

Examples

Basic usage:

assert_eq!(isize::MAX.count_zeros(), 1);
Run

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

Examples

Basic usage:

let n = -1isize;

assert_eq!(n.leading_zeros(), 0);
Run

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

Examples

Basic usage:

let n = -4isize;

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

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

Examples

Basic usage:

let n = -1isize;

assert_eq!(n.leading_ones(), 64);
Run

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

Examples

Basic usage:

let n = 3isize;

assert_eq!(n.trailing_ones(), 2);
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 = 0xaa00000000006e1isize;
let m = 0x6e10aa;

assert_eq!(n.rotate_left(12), 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 = 0x6e10aaisize;
let m = 0xaa00000000006e1;

assert_eq!(n.rotate_right(12), m);
Run

Reverses the byte order of the integer.

Examples

Basic usage:

let n = 0x1234567890123456isize;

let m = n.swap_bytes();

assert_eq!(m, 0x5634129078563412);
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 = 0x1234567890123456isize;
let m = n.reverse_bits();

assert_eq!(m, 0x6a2c48091e6a2c48);
assert_eq!(0, 0isize.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 = 0x1Aisize;

if cfg!(target_endian = "big") {
    assert_eq!(isize::from_be(n), n)
} else {
    assert_eq!(isize::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 = 0x1Aisize;

if cfg!(target_endian = "little") {
    assert_eq!(isize::from_le(n), n)
} else {
    assert_eq!(isize::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 = 0x1Aisize;

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 = 0x1Aisize;

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

niche optimization path

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

Safety

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

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

Examples

Basic usage:

assert_eq!((isize::MIN + 2).checked_sub(1), Some(isize::MIN + 1));
assert_eq!((isize::MIN + 2).checked_sub(3), None);
Run
🔬 This is a nightly-only experimental API. (unchecked_math #85122)

niche optimization path

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

Safety

This results in undefined behavior when self - rhs > isize::MAX or self - rhs < isize::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!(isize::MAX.checked_mul(1), Some(isize::MAX));
assert_eq!(isize::MAX.checked_mul(2), None);
Run
🔬 This is a nightly-only experimental API. (unchecked_math #85122)

niche optimization path

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

Safety

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

Checked integer division. Computes self / rhs, returning None if rhs == 0 or the division results in overflow.

Examples

Basic usage:

assert_eq!((isize::MIN + 1).checked_div(-1), Some(9223372036854775807));
assert_eq!(isize::MIN.checked_div(-1), None);
assert_eq!((1isize).checked_div(0), None);
Run

Checked Euclidean division. Computes self.div_euclid(rhs), returning None if rhs == 0 or the division results in overflow.

Examples

Basic usage:

assert_eq!((isize::MIN + 1).checked_div_euclid(-1), Some(9223372036854775807));
assert_eq!(isize::MIN.checked_div_euclid(-1), None);
assert_eq!((1isize).checked_div_euclid(0), None);
Run

Checked integer remainder. Computes self % rhs, returning None if rhs == 0 or the division results in overflow.

Examples

Basic usage:


assert_eq!(5isize.checked_rem(2), Some(1));
assert_eq!(5isize.checked_rem(0), None);
assert_eq!(isize::MIN.checked_rem(-1), None);
Run

Checked Euclidean remainder. Computes self.rem_euclid(rhs), returning None if rhs == 0 or the division results in overflow.

Examples

Basic usage:

assert_eq!(5isize.checked_rem_euclid(2), Some(1));
assert_eq!(5isize.checked_rem_euclid(0), None);
assert_eq!(isize::MIN.checked_rem_euclid(-1), None);
Run

Checked negation. Computes -self, returning None if self == MIN.

Examples

Basic usage:


assert_eq!(5isize.checked_neg(), Some(-5));
assert_eq!(isize::MIN.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!(0x1isize.checked_shl(4), Some(0x10));
assert_eq!(0x1isize.checked_shl(129), None);
Run
🔬 This is a nightly-only experimental API. (unchecked_math #85122)

niche optimization path

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!(0x10isize.checked_shr(4), Some(0x1));
assert_eq!(0x10isize.checked_shr(128), None);
Run
🔬 This is a nightly-only experimental API. (unchecked_math #85122)

niche optimization path

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 absolute value. Computes self.abs(), returning None if self == MIN.

Examples

Basic usage:


assert_eq!((-5isize).checked_abs(), Some(5));
assert_eq!(isize::MIN.checked_abs(), None);
Run

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

Examples

Basic usage:

assert_eq!(8isize.checked_pow(2), Some(64));
assert_eq!(isize::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!(100isize.saturating_add(1), 101);
assert_eq!(isize::MAX.saturating_add(100), isize::MAX);
assert_eq!(isize::MIN.saturating_add(-1), isize::MIN);
Run

Saturating integer subtraction. Computes self - rhs, saturating at the numeric bounds instead of overflowing.

Examples

Basic usage:

assert_eq!(100isize.saturating_sub(127), -27);
assert_eq!(isize::MIN.saturating_sub(100), isize::MIN);
assert_eq!(isize::MAX.saturating_sub(-1), isize::MAX);
Run

Saturating integer negation. Computes -self, returning MAX if self == MIN instead of overflowing.

Examples

Basic usage:

assert_eq!(100isize.saturating_neg(), -100);
assert_eq!((-100isize).saturating_neg(), 100);
assert_eq!(isize::MIN.saturating_neg(), isize::MAX);
assert_eq!(isize::MAX.saturating_neg(), isize::MIN + 1);
Run

Saturating absolute value. Computes self.abs(), returning MAX if self == MIN instead of overflowing.

Examples

Basic usage:

assert_eq!(100isize.saturating_abs(), 100);
assert_eq!((-100isize).saturating_abs(), 100);
assert_eq!(isize::MIN.saturating_abs(), isize::MAX);
assert_eq!((isize::MIN + 1).saturating_abs(), isize::MAX);
Run

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

Examples

Basic usage:


assert_eq!(10isize.saturating_mul(12), 120);
assert_eq!(isize::MAX.saturating_mul(10), isize::MAX);
assert_eq!(isize::MIN.saturating_mul(10), isize::MIN);
Run

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

Examples

Basic usage:


assert_eq!((-4isize).saturating_pow(3), -64);
assert_eq!(isize::MIN.saturating_pow(2), isize::MAX);
assert_eq!(isize::MIN.saturating_pow(3), isize::MIN);
Run

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

Examples

Basic usage:

assert_eq!(100isize.wrapping_add(27), 127);
assert_eq!(isize::MAX.wrapping_add(2), isize::MIN + 1);
Run

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

Examples

Basic usage:

assert_eq!(0isize.wrapping_sub(127), -127);
assert_eq!((-2isize).wrapping_sub(isize::MAX), isize::MAX);
Run

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

Examples

Basic usage:

assert_eq!(10isize.wrapping_mul(12), 120);
assert_eq!(11i8.wrapping_mul(12), -124);
Run

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

The only case where such wrapping can occur is when one divides MIN / -1 on a signed type (where MIN is the negative minimal value for the type); this is equivalent to -MIN, a positive value that is too large to represent in the type. In such a case, this function returns MIN itself.

Panics

This function will panic if rhs is 0.

Examples

Basic usage:

assert_eq!(100isize.wrapping_div(10), 10);
assert_eq!((-128i8).wrapping_div(-1), -128);
Run

Wrapping Euclidean division. Computes self.div_euclid(rhs), wrapping around at the boundary of the type.

Wrapping will only occur in MIN / -1 on a signed type (where MIN is the negative minimal value for the type). This is equivalent to -MIN, a positive value that is too large to represent in the type. In this case, this method returns MIN itself.

Panics

This function will panic if rhs is 0.

Examples

Basic usage:

assert_eq!(100isize.wrapping_div_euclid(10), 10);
assert_eq!((-128i8).wrapping_div_euclid(-1), -128);
Run

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

Such wrap-around never actually occurs mathematically; implementation artifacts make x % y invalid for MIN / -1 on a signed type (where MIN is the negative minimal value). In such a case, this function returns 0.

Panics

This function will panic if rhs is 0.

Examples

Basic usage:

assert_eq!(100isize.wrapping_rem(10), 0);
assert_eq!((-128i8).wrapping_rem(-1), 0);
Run

Wrapping Euclidean remainder. Computes self.rem_euclid(rhs), wrapping around at the boundary of the type.

Wrapping will only occur in MIN % -1 on a signed type (where MIN is the negative minimal value for the type). In this case, this method returns 0.

Panics

This function will panic if rhs is 0.

Examples

Basic usage:

assert_eq!(100isize.wrapping_rem_euclid(10), 0);
assert_eq!((-128i8).wrapping_rem_euclid(-1), 0);
Run

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

The only case where such wrapping can occur is when one negates MIN on a signed type (where MIN is the negative minimal value for the type); this is a positive value that is too large to represent in the type. In such a case, this function returns MIN itself.

Examples

Basic usage:

assert_eq!(100isize.wrapping_neg(), -100);
assert_eq!(isize::MIN.wrapping_neg(), isize::MIN);
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!((-1isize).wrapping_shl(7), -128);
assert_eq!((-1isize).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!((-128isize).wrapping_shr(7), -1);
assert_eq!((-128i16).wrapping_shr(64), -128);
Run

Wrapping (modular) absolute value. Computes self.abs(), wrapping around at the boundary of the type.

The only case where such wrapping can occur is when one takes the absolute value of the negative minimal value for the type; this is a positive value that is too large to represent in the type. In such a case, this function returns MIN itself.

Examples

Basic usage:

assert_eq!(100isize.wrapping_abs(), 100);
assert_eq!((-100isize).wrapping_abs(), 100);
assert_eq!(isize::MIN.wrapping_abs(), isize::MIN);
assert_eq!((-128i8).wrapping_abs() as u8, 128);
Run

Computes the absolute value of self without any wrapping or panicking.

Examples

Basic usage:

assert_eq!(100isize.unsigned_abs(), 100usize);
assert_eq!((-100isize).unsigned_abs(), 100usize);
assert_eq!((-128i8).unsigned_abs(), 128u8);
Run

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

Examples

Basic usage:

assert_eq!(3isize.wrapping_pow(4), 81);
assert_eq!(3i8.wrapping_pow(5), -13);
assert_eq!(3i8.wrapping_pow(6), -39);
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!(5isize.overflowing_add(2), (7, false));
assert_eq!(isize::MAX.overflowing_add(1), (isize::MIN, 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!(5isize.overflowing_sub(2), (3, false));
assert_eq!(isize::MIN.overflowing_sub(1), (isize::MAX, true));
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:

assert_eq!(5isize.overflowing_mul(2), (10, false));
assert_eq!(1_000_000_000i32.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. If an overflow would occur then self is returned.

Panics

This function will panic if rhs is 0.

Examples

Basic usage:


assert_eq!(5isize.overflowing_div(2), (2, false));
assert_eq!(isize::MIN.overflowing_div(-1), (isize::MIN, true));
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. If an overflow would occur then self is returned.

Panics

This function will panic if rhs is 0.

Examples

Basic usage:

assert_eq!(5isize.overflowing_div_euclid(2), (2, false));
assert_eq!(isize::MIN.overflowing_div_euclid(-1), (isize::MIN, true));
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. If an overflow would occur then 0 is returned.

Panics

This function will panic if rhs is 0.

Examples

Basic usage:


assert_eq!(5isize.overflowing_rem(2), (1, false));
assert_eq!(isize::MIN.overflowing_rem(-1), (0, true));
Run

Overflowing Euclidean remainder. Calculates self.rem_euclid(rhs).

Returns a tuple of the remainder after dividing along with a boolean indicating whether an arithmetic overflow would occur. If an overflow would occur then 0 is returned.

Panics

This function will panic if rhs is 0.

Examples

Basic usage:

assert_eq!(5isize.overflowing_rem_euclid(2), (1, false));
assert_eq!(isize::MIN.overflowing_rem_euclid(-1), (0, true));
Run

Negates self, overflowing if this is equal to the minimum value.

Returns a tuple of the negated version of self along with a boolean indicating whether an overflow happened. If self is the minimum value (e.g., i32::MIN for values of type i32), then the minimum value will be returned again and true will be returned for an overflow happening.

Examples

Basic usage:

assert_eq!(2isize.overflowing_neg(), (-2, false));
assert_eq!(isize::MIN.overflowing_neg(), (isize::MIN, 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!(0x1isize.overflowing_shl(4), (0x10, false));
assert_eq!(0x1i32.overflowing_shl(36), (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!(0x10isize.overflowing_shr(4), (0x1, false));
assert_eq!(0x10i32.overflowing_shr(36), (0x1, true));
Run

Computes the absolute value of self.

Returns a tuple of the absolute version of self along with a boolean indicating whether an overflow happened. If self is the minimum value (e.g., isize::MIN for values of type isize), then the minimum value will be returned again and true will be returned for an overflow happening.

Examples

Basic usage:

assert_eq!(10isize.overflowing_abs(), (10, false));
assert_eq!((-10isize).overflowing_abs(), (10, false));
assert_eq!((isize::MIN).overflowing_abs(), (isize::MIN, 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!(3isize.overflowing_pow(4), (81, false));
assert_eq!(3i8.overflowing_pow(5), (-13, true));
Run

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

Examples

Basic usage:

let x: isize = 2; // or any other integer type

assert_eq!(x.pow(5), 32);
Run

Calculates the quotient of Euclidean division of self by rhs.

This computes the integer q such that self = q * rhs + r, with r = self.rem_euclid(rhs) and 0 <= r < abs(rhs).

In other words, the result is self / rhs rounded to the integer q such that self >= q * rhs. If self > 0, this is equal to round towards zero (the default in Rust); if self < 0, this is equal to round towards +/- infinity.

Panics

This function will panic if rhs is 0 or the division results in overflow.

Examples

Basic usage:

let a: isize = 7; // or any other integer type
let b = 4;

assert_eq!(a.div_euclid(b), 1); // 7 >= 4 * 1
assert_eq!(a.div_euclid(-b), -1); // 7 >= -4 * -1
assert_eq!((-a).div_euclid(b), -2); // -7 >= 4 * -2
assert_eq!((-a).div_euclid(-b), 2); // -7 >= -4 * 2
Run

Calculates the least nonnegative remainder of self (mod rhs).

This is done as if by the Euclidean division algorithm – given r = self.rem_euclid(rhs), self = rhs * self.div_euclid(rhs) + r, and 0 <= r < abs(rhs).

Panics

This function will panic if rhs is 0 or the division results in overflow.

Examples

Basic usage:

let a: isize = 7; // or any other integer type
let b = 4;

assert_eq!(a.rem_euclid(b), 3);
assert_eq!((-a).rem_euclid(b), 1);
assert_eq!(a.rem_euclid(-b), 3);
assert_eq!((-a).rem_euclid(-b), 1);
Run
🔬 This is a nightly-only experimental API. (int_log #70887)

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

This method might not be optimized owing to implementation details; log2 can produce results more efficiently for base 2, and log10 can produce results more efficiently for base 10.

Panics

When the number is zero, or if the base is not at least 2; it panics in debug mode and the return value is wrapped to 0 in release mode (the only situation in which the method can return 0).

Examples

#![feature(int_log)]
assert_eq!(5isize.log(5), 1);
Run
🔬 This is a nightly-only experimental API. (int_log #70887)

Returns the base 2 logarithm of the number.

Panics

When the number is zero it panics in debug mode and the return value is wrapped to 0 in release mode (the only situation in which the method can return 0).

Examples

#![feature(int_log)]
assert_eq!(2isize.log2(), 1);
Run
🔬 This is a nightly-only experimental API. (int_log #70887)

Returns the base 10 logarithm of the number.

Panics

When the number is zero it panics in debug mode and the return value is wrapped to 0 in release mode (the only situation in which the method can return 0).

Example

#![feature(int_log)]
assert_eq!(10isize.log10(), 1);
Run
🔬 This is a nightly-only experimental API. (int_log #70887)

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

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

This method might not be optimized owing to implementation details; checked_log2 can produce results more efficiently for base 2, and checked_log10 can produce results more efficiently for base 10.

Examples

#![feature(int_log)]
assert_eq!(5isize.checked_log(5), Some(1));
Run
🔬 This is a nightly-only experimental API. (int_log #70887)

Returns the base 2 logarithm of the number.

Returns None if the number is negative or zero.

Examples

#![feature(int_log)]
assert_eq!(2isize.checked_log2(), Some(1));
Run
🔬 This is a nightly-only experimental API. (int_log #70887)

Returns the base 10 logarithm of the number.

Returns None if the number is negative or zero.

Example

#![feature(int_log)]
assert_eq!(10isize.checked_log10(), Some(1));
Run

Computes the absolute value of self.

Overflow behavior

The absolute value of isize::MIN cannot be represented as an isize, and attempting to calculate it will cause an overflow. This means that code in debug mode will trigger a panic on this case and optimized code will return isize::MIN without a panic.

Examples

Basic usage:

assert_eq!(10isize.abs(), 10);
assert_eq!((-10isize).abs(), 10);
Run

Returns a number representing sign of self.

  • 0 if the number is zero
  • 1 if the number is positive
  • -1 if the number is negative

Examples

Basic usage:

assert_eq!(10isize.signum(), 1);
assert_eq!(0isize.signum(), 0);
assert_eq!((-10isize).signum(), -1);
Run

Returns true if self is positive and false if the number is zero or negative.

Examples

Basic usage:

assert!(10isize.is_positive());
assert!(!(-10isize).is_positive());
Run

Returns true if self is negative and false if the number is zero or positive.

Examples

Basic usage:

assert!((-10isize).is_negative());
assert!(!10isize.is_negative());
Run

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

Note: This function returns an array of length 2, 4 or 8 bytes depending on the target pointer size.

Examples

let bytes = 0x1234567890123456isize.to_be_bytes();
assert_eq!(bytes, [0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]);
Run

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

Note: This function returns an array of length 2, 4 or 8 bytes depending on the target pointer size.

Examples

let bytes = 0x1234567890123456isize.to_le_bytes();
assert_eq!(bytes, [0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 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.

Note: This function returns an array of length 2, 4 or 8 bytes depending on the target pointer size.

Examples

let bytes = 0x1234567890123456isize.to_ne_bytes();
assert_eq!(
    bytes,
    if cfg!(target_endian = "big") {
        [0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]
    } else {
        [0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]
    }
);
Run

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

Note: This function returns an array of length 2, 4 or 8 bytes depending on the target pointer size.

Examples

let value = isize::from_be_bytes([0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]);
assert_eq!(value, 0x1234567890123456);
Run

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

use std::convert::TryInto;

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

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

Note: This function returns an array of length 2, 4 or 8 bytes depending on the target pointer size.

Examples

let value = isize::from_le_bytes([0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]);
assert_eq!(value, 0x1234567890123456);
Run

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

use std::convert::TryInto;

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

Create an 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.

Note: This function returns an array of length 2, 4 or 8 bytes depending on the target pointer size.

Examples

let value = isize::from_ne_bytes(if cfg!(target_endian = "big") {
    [0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]
} else {
    [0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]
});
assert_eq!(value, 0x1234567890123456);
Run

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

use std::convert::TryInto;

fn read_ne_isize(input: &mut &[u8]) -> isize {
    let (int_bytes, rest) = input.split_at(std::mem::size_of::<isize>());
    *input = rest;
    isize::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 isize::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 isize::MAX instead.

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

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

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

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

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

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.

Panics

This operation will panic if other == 0 or the division results in overflow.

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

Converts a NonZeroIsize into an isize

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

Examples

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

Converts i16 to isize losslessly.

Converts i8 to isize losslessly.

Converts u8 to isize 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

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

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 !=.

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

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 or if self / other results in overflow.

The resulting type after applying the % operator.

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

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

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. (step_trait #42168)

recently redesigned

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)

recently redesigned

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)

recently redesigned

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)

recently redesigned

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)

recently redesigned

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)

recently redesigned

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)

recently redesigned

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

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

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.

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

Performs the conversion.

Performs the conversion.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

🔬 This is a nightly-only experimental API. (toowned_clone_into #41263)

recently added

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.