Primitive Type i64 [−]
The 64-bit signed integer type.
Methods
impl i64
const fn min_value() -> i64
Returns the smallest value that can be represented by this integer type.
const fn max_value() -> i64
Returns the largest value that can be represented by this integer type.
fn from_str_radix(src: &str, radix: u32) -> Result<i64, ParseIntError>
Converts a string slice in a given base to an integer.
Leading and trailing whitespace represent an error.
Examples
Basic usage:
fn main() { assert_eq!(u32::from_str_radix("A", 16), Ok(10)); }assert_eq!(u32::from_str_radix("A", 16), Ok(10));
fn count_ones(self) -> u32
Returns the number of ones in the binary representation of self
.
Examples
Basic usage:
fn main() { let n = 0b01001100u8; assert_eq!(n.count_ones(), 3); }let n = 0b01001100u8; assert_eq!(n.count_ones(), 3);
fn count_zeros(self) -> u32
Returns the number of zeros in the binary representation of self
.
Examples
Basic usage:
fn main() { let n = 0b01001100u8; assert_eq!(n.count_zeros(), 5); }let n = 0b01001100u8; assert_eq!(n.count_zeros(), 5);
fn leading_zeros(self) -> u32
Returns the number of leading zeros in the binary representation
of self
.
Examples
Basic usage:
fn main() { let n = 0b0101000u16; assert_eq!(n.leading_zeros(), 10); }let n = 0b0101000u16; assert_eq!(n.leading_zeros(), 10);
fn trailing_zeros(self) -> u32
Returns the number of trailing zeros in the binary representation
of self
.
Examples
Basic usage:
fn main() { let n = 0b0101000u16; assert_eq!(n.trailing_zeros(), 3); }let n = 0b0101000u16; assert_eq!(n.trailing_zeros(), 3);
fn rotate_left(self, n: u32) -> i64
Shifts the bits to the left by a specified amount, n
,
wrapping the truncated bits to the end of the resulting integer.
Examples
Basic usage:
fn main() { let n = 0x0123456789ABCDEFu64; let m = 0x3456789ABCDEF012u64; assert_eq!(n.rotate_left(12), m); }let n = 0x0123456789ABCDEFu64; let m = 0x3456789ABCDEF012u64; assert_eq!(n.rotate_left(12), m);
fn rotate_right(self, n: u32) -> i64
Shifts the bits to the right by a specified amount, n
,
wrapping the truncated bits to the beginning of the resulting
integer.
Examples
Basic usage:
fn main() { let n = 0x0123456789ABCDEFu64; let m = 0xDEF0123456789ABCu64; assert_eq!(n.rotate_right(12), m); }let n = 0x0123456789ABCDEFu64; let m = 0xDEF0123456789ABCu64; assert_eq!(n.rotate_right(12), m);
fn swap_bytes(self) -> i64
Reverses the byte order of the integer.
Examples
Basic usage:
fn main() { let n = 0x0123456789ABCDEFu64; let m = 0xEFCDAB8967452301u64; assert_eq!(n.swap_bytes(), m); }let n = 0x0123456789ABCDEFu64; let m = 0xEFCDAB8967452301u64; assert_eq!(n.swap_bytes(), m);
fn from_be(x: i64) -> i64
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:
fn main() { let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "big") { assert_eq!(u64::from_be(n), n) } else { assert_eq!(u64::from_be(n), n.swap_bytes()) } }let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "big") { assert_eq!(u64::from_be(n), n) } else { assert_eq!(u64::from_be(n), n.swap_bytes()) }
fn from_le(x: i64) -> i64
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:
fn main() { let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "little") { assert_eq!(u64::from_le(n), n) } else { assert_eq!(u64::from_le(n), n.swap_bytes()) } }let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "little") { assert_eq!(u64::from_le(n), n) } else { assert_eq!(u64::from_le(n), n.swap_bytes()) }
fn to_be(self) -> i64
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:
fn main() { let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "big") { assert_eq!(n.to_be(), n) } else { assert_eq!(n.to_be(), n.swap_bytes()) } }let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "big") { assert_eq!(n.to_be(), n) } else { assert_eq!(n.to_be(), n.swap_bytes()) }
fn to_le(self) -> i64
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:
fn main() { let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "little") { assert_eq!(n.to_le(), n) } else { assert_eq!(n.to_le(), n.swap_bytes()) } }let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "little") { assert_eq!(n.to_le(), n) } else { assert_eq!(n.to_le(), n.swap_bytes()) }
fn checked_add(self, other: i64) -> Option<i64>
Checked integer addition. Computes self + other
, returning None
if overflow occurred.
Examples
Basic usage:
fn main() { assert_eq!(5u16.checked_add(65530), Some(65535)); assert_eq!(6u16.checked_add(65530), None); }assert_eq!(5u16.checked_add(65530), Some(65535)); assert_eq!(6u16.checked_add(65530), None);
fn checked_sub(self, other: i64) -> Option<i64>
Checked integer subtraction. Computes self - other
, returning
None
if underflow occurred.
Examples
Basic usage:
fn main() { assert_eq!((-127i8).checked_sub(1), Some(-128)); assert_eq!((-128i8).checked_sub(1), None); }assert_eq!((-127i8).checked_sub(1), Some(-128)); assert_eq!((-128i8).checked_sub(1), None);
fn checked_mul(self, other: i64) -> Option<i64>
Checked integer multiplication. Computes self * other
, returning
None
if underflow or overflow occurred.
Examples
Basic usage:
fn main() { assert_eq!(5u8.checked_mul(51), Some(255)); assert_eq!(5u8.checked_mul(52), None); }assert_eq!(5u8.checked_mul(51), Some(255)); assert_eq!(5u8.checked_mul(52), None);
fn checked_div(self, other: i64) -> Option<i64>
Checked integer division. Computes self / other
, returning None
if other == 0
or the operation results in underflow or overflow.
Examples
Basic usage:
fn main() { assert_eq!((-127i8).checked_div(-1), Some(127)); assert_eq!((-128i8).checked_div(-1), None); assert_eq!((1i8).checked_div(0), None); }assert_eq!((-127i8).checked_div(-1), Some(127)); assert_eq!((-128i8).checked_div(-1), None); assert_eq!((1i8).checked_div(0), None);
fn saturating_add(self, other: i64) -> i64
Saturating integer addition. Computes self + other
, saturating at
the numeric bounds instead of overflowing.
Examples
Basic usage:
fn main() { assert_eq!(100i8.saturating_add(1), 101); assert_eq!(100i8.saturating_add(127), 127); }assert_eq!(100i8.saturating_add(1), 101); assert_eq!(100i8.saturating_add(127), 127);
fn saturating_sub(self, other: i64) -> i64
Saturating integer subtraction. Computes self - other
, saturating
at the numeric bounds instead of overflowing.
Examples
Basic usage:
fn main() { assert_eq!(100i8.saturating_sub(127), -27); assert_eq!((-100i8).saturating_sub(127), -128); }assert_eq!(100i8.saturating_sub(127), -27); assert_eq!((-100i8).saturating_sub(127), -128);
fn wrapping_add(self, rhs: i64) -> i64
Wrapping (modular) addition. Computes self + other
,
wrapping around at the boundary of the type.
Examples
Basic usage:
fn main() { assert_eq!(100i8.wrapping_add(27), 127); assert_eq!(100i8.wrapping_add(127), -29); }assert_eq!(100i8.wrapping_add(27), 127); assert_eq!(100i8.wrapping_add(127), -29);
fn wrapping_sub(self, rhs: i64) -> i64
Wrapping (modular) subtraction. Computes self - other
,
wrapping around at the boundary of the type.
Examples
Basic usage:
fn main() { assert_eq!(0i8.wrapping_sub(127), -127); assert_eq!((-2i8).wrapping_sub(127), 127); }assert_eq!(0i8.wrapping_sub(127), -127); assert_eq!((-2i8).wrapping_sub(127), 127);
fn wrapping_mul(self, rhs: i64) -> i64
Wrapping (modular) multiplication. Computes self * other
, wrapping around at the boundary of the type.
Examples
Basic usage:
fn main() { assert_eq!(10i8.wrapping_mul(12), 120); assert_eq!(11i8.wrapping_mul(12), -124); }assert_eq!(10i8.wrapping_mul(12), 120); assert_eq!(11i8.wrapping_mul(12), -124);
fn wrapping_div(self, rhs: i64) -> i64
Wrapping (modular) division. Computes self / other
,
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.
Examples
Basic usage:
fn main() { assert_eq!(100u8.wrapping_div(10), 10); assert_eq!((-128i8).wrapping_div(-1), -128); }assert_eq!(100u8.wrapping_div(10), 10); assert_eq!((-128i8).wrapping_div(-1), -128);
fn wrapping_rem(self, rhs: i64) -> i64
Wrapping (modular) remainder. Computes self % other
,
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
.
Examples
Basic usage:
fn main() { assert_eq!(100i8.wrapping_rem(10), 0); assert_eq!((-128i8).wrapping_rem(-1), 0); }assert_eq!(100i8.wrapping_rem(10), 0); assert_eq!((-128i8).wrapping_rem(-1), 0);
fn wrapping_neg(self) -> i64
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:
fn main() { assert_eq!(100i8.wrapping_neg(), -100); assert_eq!((-128i8).wrapping_neg(), -128); }assert_eq!(100i8.wrapping_neg(), -100); assert_eq!((-128i8).wrapping_neg(), -128);
fn wrapping_shl(self, rhs: u32) -> i64
Panic-free bitwise shift-left; yields self << mask(rhs)
,
where mask
removes any high-order bits of rhs
that
would cause the shift to exceed the bitwidth of the type.
Examples
Basic usage:
fn main() { assert_eq!(1u8.wrapping_shl(7), 128); assert_eq!(1u8.wrapping_shl(8), 1); }assert_eq!(1u8.wrapping_shl(7), 128); assert_eq!(1u8.wrapping_shl(8), 1);
fn wrapping_shr(self, rhs: u32) -> i64
Panic-free bitwise shift-left; yields self >> mask(rhs)
,
where mask
removes any high-order bits of rhs
that
would cause the shift to exceed the bitwidth of the type.
Examples
Basic usage:
fn main() { assert_eq!(128u8.wrapping_shr(7), 1); assert_eq!(128u8.wrapping_shr(8), 128); }assert_eq!(128u8.wrapping_shr(7), 1); assert_eq!(128u8.wrapping_shr(8), 128);
fn pow(self, exp: u32) -> i64
Raises self to the power of exp
, using exponentiation by squaring.
Examples
Basic usage:
fn main() { let x: i32 = 2; // or any other integer type assert_eq!(x.pow(4), 16); }let x: i32 = 2; // or any other integer type assert_eq!(x.pow(4), 16);
fn abs(self) -> i64
Computes the absolute value of self
.
Overflow behavior
The absolute value of i32::min_value()
cannot be represented as an
i32
, 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 i32::min_value()
without a panic.
Examples
Basic usage:
fn main() { assert_eq!(10i8.abs(), 10); assert_eq!((-10i8).abs(), 10); }assert_eq!(10i8.abs(), 10); assert_eq!((-10i8).abs(), 10);
fn signum(self) -> i64
Returns a number representing sign of self
.
0
if the number is zero1
if the number is positive-1
if the number is negative
Examples
Basic usage:
fn main() { assert_eq!(10i8.signum(), 1); assert_eq!(0i8.signum(), 0); assert_eq!((-10i8).signum(), -1); }assert_eq!(10i8.signum(), 1); assert_eq!(0i8.signum(), 0); assert_eq!((-10i8).signum(), -1);
fn is_positive(self) -> bool
Returns true
if self
is positive and false
if the number
is zero or negative.
Examples
Basic usage:
fn main() { assert!(10i8.is_positive()); assert!(!(-10i8).is_positive()); }assert!(10i8.is_positive()); assert!(!(-10i8).is_positive());
fn is_negative(self) -> bool
Returns true
if self
is negative and false
if the number
is zero or positive.
Examples
Basic usage:
fn main() { assert!((-10i8).is_negative()); assert!(!10i8.is_negative()); }assert!((-10i8).is_negative()); assert!(!10i8.is_negative());
Trait Implementations
impl OverflowingOps for i64
fn overflowing_add(self, rhs: i64) -> (i64, bool)
fn overflowing_sub(self, rhs: i64) -> (i64, bool)
fn overflowing_mul(self, rhs: i64) -> (i64, bool)
fn overflowing_div(self, rhs: i64) -> (i64, bool)
fn overflowing_rem(self, rhs: i64) -> (i64, bool)
fn overflowing_shl(self, rhs: u32) -> (i64, bool)
fn overflowing_shr(self, rhs: u32) -> (i64, bool)
fn overflowing_neg(self) -> (i64, bool)
impl Zero for i64
impl One for i64
impl FromStr for i64
type Err = ParseIntError
fn from_str(src: &str) -> Result<i64, ParseIntError>
impl From<i8> for i64
impl From<i16> for i64
impl From<i32> for i64
impl From<u8> for i64
impl From<u16> for i64
impl From<u32> for i64
impl Zeroable for i64
impl Add<i64> for i64
impl<'a> Add<i64> for &'a i64
impl<'a> Add<&'a i64> for i64
impl<'a, 'b> Add<&'a i64> for &'b i64
impl Sub<i64> for i64
impl<'a> Sub<i64> for &'a i64
impl<'a> Sub<&'a i64> for i64
impl<'a, 'b> Sub<&'a i64> for &'b i64
impl Mul<i64> for i64
impl<'a> Mul<i64> for &'a i64
impl<'a> Mul<&'a i64> for i64
impl<'a, 'b> Mul<&'a i64> for &'b i64
impl Div<i64> for i64
This operation rounds towards zero, truncating any fractional part of the exact result.
impl<'a> Div<i64> for &'a i64
impl<'a> Div<&'a i64> for i64
impl<'a, 'b> Div<&'a i64> for &'b i64
impl Rem<i64> for i64
This operation satisfies n % d == n - (n / d) * d
. The
result has the same sign as the left operand.