Crate const_fn

An attribute for easy generation of a const function with conditional compilations.

Examples

When using like the following functions to control unstable features:

[features]
const = []

It can be written as follows:

#![cfg_attr(feature = "const", feature(const_fn, const_let, const_vec_new))]

#[const_fn(feature = "const")]
pub const fn empty_vec<T>() -> Vec<T> {
    let vec = Vec::new();
    vec
}

Code like this will be generated:

#![cfg_attr(feature = "const", feature(const_fn, const_let, const_vec_new))]

#[cfg(feature = "const")]
pub const fn empty_vec<T>() -> Vec<T> {
    let vec = Vec::new();
    vec
}

#[cfg(not(feature = "const"))]
pub fn empty_vec<T>() -> Vec<T> {
    let vec = Vec::new();
    vec
}

Rust Version

The current minimum required Rust version is 1.30.

Attribute Macros

const_fn

An attribute for easy generation of a const function with conditional compilations.