ScratchBuffer<dyn Trait> is like Vec<Box<dyn Trait>>, but with an optimization that avoids reallocations. It allows to store multiple items of the same type in a continous chunk of memory, and get a slice. When the ScratchBuffer is cleared, it can be re-used for multiple items of a different type. It doesn't re-allocate memory when not needed, even when re-used as a different type.
This example stores multiple values the ScratchBuffer and accesses them.
(push(...) requires the "unstable" feature (nightly only))
use scratchbuffer::ScratchBuffer;
let mut buf = ScratchBuffer::new();
// to use the scratchbuffer, you need to clear it, and tell which type you want to use
let mut u32buf = buf.clear_and_use_as::<u32>();
u32buf.push(123);
u32buf.push(456);
assert_eq!(&[123u32, 456], u32buf.as_slice());
// now use the scratchbuffer with a different type.
// in this case, no memory-allocations are needed, because the scratchbuffer
// can re-use the memory it has allocated for u32buf
let u16buf = buf.clear_and_use_as::<u16>();
u16buf.push(345);
u16buf.push(678);
assert_eq!(&[345u16, 678], u16buf.as_slice());This crate should also work without std (with alloc). No additional configuration required.
This project is licensed under either of
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
- Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.