Crate nonmaxunsigned

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§NonMax-Unsigned

Crates.io docs.rs Dependency status

This crate provides an implementation for non-max integer types with null-pointer-optimization.

This crate is usable in a no-std environment.

§Example

use nonmaxunsigned::NonMaxU8;

fn main() {
    let a = NonMaxU8::new(5).unwrap();
    let b = NonMaxU8::new(12).unwrap();

    assert_eq!(NonMaxU8::new(17).unwrap(), a + b);
    assert_eq!(None, NonMaxU8::new(u8::MAX));
}

§Features

§endian-conversion

This feature provides access to little and big endian versions of the non-max integer types as well as conversions between them. The native version for the non-max integers is just a type alias for the correct endianness.

non_max.get() will always return the native endian integer.

use nonmaxunsigned::{NonMaxU32Le, NonMaxU32Be, NonMaxU32};

fn main() {
    let native = NonMaxU32::new(37).unwrap();
    let little = native.to_le();
    let big = native.to_be();

    assert_eq!(little.get(), big.get());
    assert_eq!(native.get(), big.get());
    assert_eq!(native.get(), little.get());

    assert_eq!(little.to_native(), native);
    assert_eq!(little.to_be(), big);
}

§Similar Crates

There are a few similar crates already existing on crates.io:

Unlike those crates this implementation does not NonZero. Those crates store the value as value ^ max which is never 0 as long as value != max. However this means the binary/hex representation of the stored value is hard to parse.

This implementation instead relies on a large enum NonMaxU8Internal which has 254 variants. Such an enum also leads to null-pointer-optimization but does not require the xor trick to prevent 0 values. Instead it relies on core::mem::transmute_copy.

§License

Licensed under either of

at your option.

Structs§

NonMaxU8
NonMaxU8 is a nonmax, native-endian version of u8.
NonMaxU16Be
NonMaxU16Be is a nonmax, big-endian version of u16.
NonMaxU16Le
NonMaxU16Le is a nonmax, little-endian version of u16.
NonMaxU32Be
NonMaxU32Be is a nonmax, big-endian version of u32.
NonMaxU32Le
NonMaxU32Le is a nonmax, little-endian version of u32.
NonMaxU64Be
NonMaxU64Be is a nonmax, big-endian version of u64.
NonMaxU64Le
NonMaxU64Le is a nonmax, little-endian version of u64.
PrimitiveIsMaxError
Error type returned by TryFrom from primitive integer into nonmax versions

Type Aliases§

NonMaxU16
NonMaxU16 is a nonmax, native-endian version of u16.
NonMaxU32
NonMaxU32 is a nonmax, native-endian version of u32.
NonMaxU64
NonMaxU64 is a nonmax, native-endian version of u64.