Constant syntax::feature_gate::EXPLAIN_BOX_SYNTAX[][src]

const EXPLAIN_BOX_SYNTAX: &'static str = "box expression syntax is experimental; you can call `Box::new` instead."
🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?