Tracking Issue for `int_from_ascii`

Feature gate: #![feature(int_from_ascii)]

This is a tracking issue for int_from_ascii, providing equivalent methods to {usize,u8,u16,u32,u64,u128,isize,i8,i16,i32,i64,i128}::from_str() and from_str_radix() that allow working directly on byte slices, in order to skip UTF-8 validation.

Public API

For each integer type X (usize, u8, u16, u32, u64, u128, isize, i8, i16, i32, i64, i128):

// core::num

impl X {
    pub const fn from_ascii_bytes<T>(src: T) -> Result<X, ParseIntError>
    where
        T: [const] AsRef<[u8]> + [const] core::marker::Destruct;

    pub const fn from_ascii_bytes_radix<T>(src: T, radix: u32) -> Result<X, ParseIntError>
    where
        T: [const] AsRef<[u8]> + [const] core::marker::Destruct;
}

impl NonZero<X> {
    pub const fn from_ascii_bytes<T>(src: T) -> Result<Self, ParseIntError>
    where
        T: [const] AsRef<[u8]> + [const] core::marker::Destruct;

    pub const fn from_ascii_bytes_radix<T>(src: T, radix: u32) -> Result<Self, ParseIntError>
    where
        T: [const] AsRef<[u8]> + [const] core::marker::Destruct;
}

// core::num

impl X {
    pub const fn from_ascii(src: &[u8]) -> Result<X, ParseIntError>;
    pub const fn from_ascii_radix(src: &[u8], radix: u32) -> Result<X, ParseIntError>;
}

impl NonZero<X> {
    pub const fn from_ascii(src: &[u8]) -> Result<Self, ParseIntError>;
    pub const fn from_ascii_radix(src: &[u8], radix: u32) -> Result<Self, ParseIntError>;
}

Steps / History

• Abandoned implementation: #105206
• API change proposal: https://github.com/rust-lang/libs-team/issues/469
• Implementation for T: #134824
• Implementation for NonZero<T>: #152267
• from_ascii -> from_ascii_bytes and src: &[u8] -> src: impl AsRef<[u8]>: #159554
• Final comment period (FCP)^1
• Stabilization PR

Unresolved Questions

• Stabilize #152193 first

Start by reviewing the API change proposal in libs-team issue #469, the implementation PRs #134824, #152267, and #159554, and the stabilization guide linked in the FCP checklist. Done means completing the final comment period and landing a stabilization PR for the documented integer and NonZero APIs.