Struct tikv_util::metrics::process_linux::BOOT_TIME[][src]

struct BOOT_TIME {
    __private_field: (),
}

Fields

__private_field: ()

Methods from Deref<Target = Option<f64>>

#[must_use = "if you intended to assert that this has a value, consider `.unwrap()` instead"]pub const fn is_some(&self) -> bool1.0.0 (const: 1.48.0)[src]

Returns true if the option is a Some value.

Examples

let x: Option<u32> = Some(2);
assert_eq!(x.is_some(), true);

let x: Option<u32> = None;
assert_eq!(x.is_some(), false);

#[must_use = "if you intended to assert that this doesn't have a value, consider \ `.and_then(|| panic!(\"`Option` had a value when expected `None`\"))` instead"]pub const fn is_none(&self) -> bool1.0.0 (const: 1.48.0)[src]

Returns true if the option is a None value.

Examples

let x: Option<u32> = Some(2);
assert_eq!(x.is_none(), false);

let x: Option<u32> = None;
assert_eq!(x.is_none(), true);

#[must_use]pub fn contains<U>(&self, x: &U) -> bool where
    U: PartialEq<T>, 
[src]

🔬 This is a nightly-only experimental API. (option_result_contains)

Returns true if the option is a Some value containing the given value.

Examples

#![feature(option_result_contains)]

let x: Option<u32> = Some(2);
assert_eq!(x.contains(&2), true);

let x: Option<u32> = Some(3);
assert_eq!(x.contains(&2), false);

let x: Option<u32> = None;
assert_eq!(x.contains(&2), false);

pub const fn as_ref(&self) -> Option<&T>1.0.0 (const: 1.48.0)[src]

Converts from &Option<T> to Option<&T>.

Examples

Converts an Option<String> into an Option<usize>, preserving the original. The map method takes the self argument by value, consuming the original, so this technique uses as_ref to first take an Option to a reference to the value inside the original.

let text: Option<String> = Some("Hello, world!".to_string());
// First, cast `Option<String>` to `Option<&String>` with `as_ref`,
// then consume *that* with `map`, leaving `text` on the stack.
let text_length: Option<usize> = text.as_ref().map(|s| s.len());
println!("still can print text: {:?}", text);

pub fn as_pin_ref(self: Pin<&Option<T>>) -> Option<Pin<&T>>1.33.0[src]

Converts from Pin<&Option<T>> to Option<Pin<&T>>.

pub fn as_pin_mut(self: Pin<&mut Option<T>>) -> Option<Pin<&mut T>>1.33.0[src]

Converts from Pin<&mut Option<T>> to Option<Pin<&mut T>>.

pub const fn iter(&self) -> Iter<'_, T>1.0.0[src]

Returns an iterator over the possibly contained value.

Examples

let x = Some(4);
assert_eq!(x.iter().next(), Some(&4));

let x: Option<u32> = None;
assert_eq!(x.iter().next(), None);

pub fn as_deref(&self) -> Option<&<T as Deref>::Target>1.40.0[src]

Converts from Option<T> (or &Option<T>) to Option<&T::Target>.

Leaves the original Option in-place, creating a new one with a reference to the original one, additionally coercing the contents via Deref.

Examples

let x: Option<String> = Some("hey".to_owned());
assert_eq!(x.as_deref(), Some("hey"));

let x: Option<String> = None;
assert_eq!(x.as_deref(), None);

Trait Implementations

impl Deref for BOOT_TIME[src]

type Target = Option<f64>

The resulting type after dereferencing.

impl LazyStatic for BOOT_TIME[src]

Auto Trait Implementations

impl RefUnwindSafe for BOOT_TIME

impl Send for BOOT_TIME

impl Sync for BOOT_TIME

impl Unpin for BOOT_TIME

impl UnwindSafe for BOOT_TIME

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> From<T> for T[src]

impl<T> Instrument for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> Pointable for T[src]

type Init = T

The type for initializers.

impl<T> Same<T> for T[src]

type Output = T

Should always be Self

impl<T> Sealed<T> for T where
    T: ?Sized
[src]

impl<T> SendSyncUnwindSafe for T where
    T: Send + Sync + UnwindSafe + ?Sized
[src]

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.

impl<V, T> VZip<V> for T where
    V: MultiLane<T>, 
[src]