[][src]Function syntax_ext::deriving::generic::cs_fold_fields

pub fn cs_fold_fields<'a, F>(
    use_foldl: bool,
    f: F,
    base: P<Expr>,
    cx: &mut ExtCtxt,
    all_fields: &[FieldInfo<'a>]
) -> P<Expr> where
    F: FnMut(&mut ExtCtxt, Span, P<Expr>, P<Expr>, &[P<Expr>]) -> P<Expr>, 
🔬 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?