pub trait Cwrite<Ctx: Copy, I = usize>: Index<I> + IndexMut<RangeFrom<I>> {
fn cwrite<N: IntoCtx<Ctx, <Self as Index<RangeFrom<I>>>::Output>>(
&mut self,
n: N,
offset: I
)
where
Ctx: Default,
{ ... }
fn cwrite_with<N: IntoCtx<Ctx, <Self as Index<RangeFrom<I>>>::Output>>(
&mut self,
n: N,
offset: I,
ctx: Ctx
) { ... }
}
Expand description
Core-write - core, no_std friendly trait for writing basic types into byte buffers. Cannot fail
unless the buffer is too small, in which case an assert fires and the program panics.
Similar to Cread, if your type implements IntoCtx
then you can cwrite(your_type, offset)
.
Example
use scroll::{ctx, Cwrite};
#[repr(packed)]
struct Bar {
foo: i32,
bar: u32,
}
impl ctx::IntoCtx<scroll::Endian> for Bar {
fn into_ctx(self, bytes: &mut [u8], ctx: scroll::Endian) {
use scroll::Cwrite;
bytes.cwrite_with(self.foo, 0, ctx);
bytes.cwrite_with(self.bar, 4, ctx);
}
}
let bar = Bar { foo: -1, bar: 0xdeadbeef };
let mut bytes = [0x0; 16];
bytes.cwrite::<Bar>(bar, 0);
Provided methods
Writes n
into Self
at offset
; uses default context.
For the primitive types, this will be the target machine’s endianness.
Example
use scroll::{Cwrite, Cread};
let mut bytes = [0x0; 16];
bytes.cwrite::<i64>(42, 0);
bytes.cwrite::<u32>(0xdeadbeef, 8);
assert_eq!(bytes.cread::<i64>(0), 42);
assert_eq!(bytes.cread::<u32>(8), 0xdeadbeef);
Writes n
into Self
at offset
with ctx
Example
use scroll::{Cwrite, Cread, LE, BE};
let mut bytes = [0x0; 0x10];
bytes.cwrite_with::<i64>(42, 0, LE);
bytes.cwrite_with::<u32>(0xdeadbeef, 8, BE);
assert_eq!(bytes.cread_with::<i64>(0, LE), 42);
assert_eq!(bytes.cread_with::<u32>(8, LE), 0xefbeadde);