Trait CheckedLogBase2 

pub trait CheckedLogBase2 {
    type Output;

    // Required method
    fn checked_log_base_2(self) -> Option<Self::Output>;
}

Calculates the base-2 logarithm of a number, or returns None if the number is not a perfect power of 2.

Required Associated Types

type Output

Required Methods

fn checked_log_base_2(self) -> Option<Self::Output>

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl CheckedLogBase2 for f32

fn checked_log_base_2(self) -> Option<i64>

Returns the base-2 logarithm of a positive float If the float is not a power of 2, None is returned.

$$ f(x) = \begin{cases} \operatorname{Some}(\log_2 x) & \text{if} \quad \log_2 x \in \Z, \\ \operatorname{None} & \textrm{otherwise}. \end{cases} $$

Worst-case complexity

Constant time and additional memory.

Panics

Panics if self is infinite, NaN, or less than or equal to zero.

Examples

See here.

type Output = i64

impl CheckedLogBase2 for f64

fn checked_log_base_2(self) -> Option<i64>

Returns the base-2 logarithm of a positive float If the float is not a power of 2, None is returned.

$$ f(x) = \begin{cases} \operatorname{Some}(\log_2 x) & \text{if} \quad \log_2 x \in \Z, \\ \operatorname{None} & \textrm{otherwise}. \end{cases} $$

Worst-case complexity

Constant time and additional memory.

Panics

Panics if self is infinite, NaN, or less than or equal to zero.

Examples

See here.

type Output = i64

impl CheckedLogBase2 for u8

fn checked_log_base_2(self) -> Option<u64>

Returns the base-2 logarithm of a positive integer. If the integer is not a power of 2, None is returned.

$$ f(x) = \begin{cases} \operatorname{Some}(\log_2 x) & \text{if} \quad \log_2 x \in \Z, \\ \operatorname{None} & \textrm{otherwise}. \end{cases} $$

Worst-case complexity

Constant time and additional memory.

Panics

Panics if self is 0.

Examples

See here.

type Output = u64

impl CheckedLogBase2 for u16

fn checked_log_base_2(self) -> Option<u64>

Returns the base-2 logarithm of a positive integer. If the integer is not a power of 2, None is returned.

$$ f(x) = \begin{cases} \operatorname{Some}(\log_2 x) & \text{if} \quad \log_2 x \in \Z, \\ \operatorname{None} & \textrm{otherwise}. \end{cases} $$

Worst-case complexity

Constant time and additional memory.

Panics

Panics if self is 0.

Examples

See here.

type Output = u64

impl CheckedLogBase2 for u32

fn checked_log_base_2(self) -> Option<u64>

Returns the base-2 logarithm of a positive integer. If the integer is not a power of 2, None is returned.

$$ f(x) = \begin{cases} \operatorname{Some}(\log_2 x) & \text{if} \quad \log_2 x \in \Z, \\ \operatorname{None} & \textrm{otherwise}. \end{cases} $$

Worst-case complexity

Constant time and additional memory.

Panics

Panics if self is 0.

Examples

See here.

type Output = u64

impl CheckedLogBase2 for u64

fn checked_log_base_2(self) -> Option<u64>

Returns the base-2 logarithm of a positive integer. If the integer is not a power of 2, None is returned.

$$ f(x) = \begin{cases} \operatorname{Some}(\log_2 x) & \text{if} \quad \log_2 x \in \Z, \\ \operatorname{None} & \textrm{otherwise}. \end{cases} $$

Worst-case complexity

Constant time and additional memory.

Panics

Panics if self is 0.

Examples

See here.

type Output = u64

impl CheckedLogBase2 for u128

fn checked_log_base_2(self) -> Option<u64>

Returns the base-2 logarithm of a positive integer. If the integer is not a power of 2, None is returned.

$$ f(x) = \begin{cases} \operatorname{Some}(\log_2 x) & \text{if} \quad \log_2 x \in \Z, \\ \operatorname{None} & \textrm{otherwise}. \end{cases} $$

Worst-case complexity

Constant time and additional memory.

Panics

Panics if self is 0.

Examples

See here.

type Output = u64

impl CheckedLogBase2 for usize

fn checked_log_base_2(self) -> Option<u64>

Returns the base-2 logarithm of a positive integer. If the integer is not a power of 2, None is returned.

$$ f(x) = \begin{cases} \operatorname{Some}(\log_2 x) & \text{if} \quad \log_2 x \in \Z, \\ \operatorname{None} & \textrm{otherwise}. \end{cases} $$

Worst-case complexity

Constant time and additional memory.

Panics

Panics if self is 0.

Examples

See here.

type Output = u64

Implementors