Function rustc_builtin_macros::deriving::default::expand_deriving_default

source ยท 
pub(crate) fn expand_deriving_default(
    cx: &ExtCtxt<'_>,
    span: Span,
    mitem: &MetaItem,
    item: &Annotatable,
    push: &mut dyn FnMut(Annotatable),
    is_const: bool,
)