Trait bones_schema::alloc::LayoutExt

pub trait LayoutExt {
    // Required methods
    fn repeat(&self, n: usize) -> Result<(Layout, usize), LayoutError>;
    fn padding_needed_for(&self, align: usize) -> usize;
}

Extension trait for the Layout type that copies useful nightly functions so that we can use them on stable.

Required Methods

fn repeat(&self, n: usize) -> Result<(Layout, usize), LayoutError>

Creates a layout describing the record for n instances of self, with a suitable amount of padding between each to ensure that each instance is given its requested size and alignment. On success, returns (k, offs) where k is the layout of the array and offs is the distance between the start of each element in the array.

On arithmetic overflow, returns LayoutError.

fn padding_needed_for(&self, align: usize) -> usize

to ensure that the following address will satisfy align (measured in bytes).

e.g., if self.size() is 9, then self.padding_needed_for(4) returns 3, because that is the minimum number of bytes of padding required to get a 4-aligned address (assuming that the corresponding memory block starts at a 4-aligned address).

The return value of this function has no meaning if align is not a power-of-two.

Note that the utility of the returned value requires align to be less than or equal to the alignment of the starting address for the whole allocated block of memory. One way to satisfy this constraint is to ensure align <= self.align().

Implementations on Foreign Types

impl LayoutExt for Layout

fn padding_needed_for(&self, align: usize) -> usize

fn repeat(&self, n: usize) -> Result<(Self, usize), LayoutError>

Implementors