Function has_feature

build.rs:227–232

Test whether the rustc at `var("RUSTC")` supports the given feature.

(feature: &str)

/// Test whether the rustc at `var("RUSTC")` supports the given feature.
fn has_feature(feature: &str) -> bool {
    can_compile(format!(
        "#![allow(stable_features)]\n#![feature({})]",
        feature
    ))
}

/// Test whether the rustc at `var("RUSTC")` can compile the given code.
fn can_compile<T: AsRef<str>>(test: T) -> bool {