I'm trying to create a function arg and other things in syn
and often I see a need for a span:
FnArg::Typed(PatType {
attrs: vec![],
pat: Box::new(Pat::Ident(PatIdent {
attrs: vec![],
by_ref: Some(Ref {
span: ?,
}),
mutability: None,
ident: Ident::new(struct_name.as_str(), ?),
subpat: None,
})),
colon_token: Colon{
spans: item_impl.,
},
ty: todo!(),
})
which is not even from syn
but from proc_macro
.
What exactly is a Span
and what do I need to put in span
above?