Struct crndm::cell::VCell

pub struct VCell<T: Default + VSafe + ?Sized, A: MemPool> { /* fields omitted */ }

A persistent memory location containing a volatile data

The underlying data is valid throughout of the course of a single pool lifetime. When the pool is reopened, the data is back to its default value. Type T in VCell<T> should implement Default and VSafe.

Examples

use crndm::default::*;
use std::cell::RefCell;
 
type P = BuddyAlloc;
 
#[derive(Default)]
struct Root {
    v: VCell<RefCell<i32>>
}

let root = P::open::<Root>("foo.pool", O_CF).unwrap();
     
P::transaction(|j| {
    let mut v = root.v.borrow_mut();
    assert_eq!(*v, i32::default());
    *v = 20; // This value is volatile and resets on restart
}).unwrap();

Implementations

impl<T: Default + VSafe, A: MemPool> VCell<T, A>

pub fn new(v: T) -> Self

Trait Implementations

impl<T: Default + VSafe, A: MemPool> Default for VCell<T, A>

pub fn default() -> Self

Returns the "default value" for a type.

impl<T: Default + VSafe, A: MemPool> Deref for VCell<T, A>

type Target = T

The resulting type after dereferencing.

pub fn deref(&self) -> &T

Dereferences the value.

impl<T: Default + VSafe, A: MemPool> DerefMut for VCell<T, A>

pub fn deref_mut(&mut self) -> &mut T

Mutably dereferences the value.

impl<T: Default + VSafe + ?Sized, A: MemPool> Drop for VCell<T, A>

pub fn drop(&mut self)

Executes the destructor for this type.

impl<T: Default + VSafe + Eq + Copy, A: MemPool> Eq for VCell<T, A>

impl<T: Default + VSafe + Ord + Copy, A: MemPool> Ord for VCell<T, A>

pub fn cmp(&self, other: &VCell<T, A>) -> Ordering

This method returns an Ordering between self and other.

#[must_use]pub fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]pub fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<T: Default + VSafe + ?Sized, A: MemPool> PSafe for VCell<T, A>

impl<T: Default + VSafe + PartialEq + Copy, A: MemPool> PartialEq<T> for VCell<T, A>

pub fn eq(&self, other: &T) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<T: Default + VSafe + PartialEq + Copy, A: MemPool> PartialEq<VCell<T, A>> for VCell<T, A>

pub fn eq(&self, other: &VCell<T, A>) -> bool

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<T: Default + VSafe + PartialOrd + Copy, A: MemPool> PartialOrd<T> for VCell<T, A>

pub fn partial_cmp(&self, other: &T) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

pub fn lt(&self, other: &T) -> bool

This method tests less than (for self and other) and is used by the < operator.

pub fn le(&self, other: &T) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

pub fn gt(&self, other: &T) -> bool

This method tests greater than (for self and other) and is used by the > operator.

pub fn ge(&self, other: &T) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: Default + VSafe + PartialOrd + Copy, A: MemPool> PartialOrd<VCell<T, A>> for VCell<T, A>

pub fn partial_cmp(&self, other: &VCell<T, A>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

pub fn lt(&self, other: &VCell<T, A>) -> bool

This method tests less than (for self and other) and is used by the < operator.

pub fn le(&self, other: &VCell<T, A>) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

pub fn gt(&self, other: &VCell<T, A>) -> bool

This method tests greater than (for self and other) and is used by the > operator.

pub fn ge(&self, other: &VCell<T, A>) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T: Default + VSafe + ?Sized, A: MemPool> Send for VCell<T, A>

Safe to transfer between thread boundaries

impl<T, A: MemPool> !Sync for VCell<T, A>

Not safe for thread data sharing