我用syn来解析 rust 迹代码.当我用field.ty读取一个命名字段的类型时，我得到了syn::Type.当我用quote!{#ty}.to_string()打印时，我得到了"Option<String>".
我怎么能只拿到"String"？我想用"Option<String>"代替#ty.
我想生成如下代码:
impl Foo {
pub set_bar(&mut self, v: String) {
self.bar = Some(v);
}
}
从
struct Foo {
bar: Option<String>
}
我的try :
let ast: DeriveInput = parse_macro_input!(input as DeriveInput);
let data: Data = ast.data;
match data {
Data::Struct(ref data) => match data.fields {
Fields::Named(ref fields) => {
fields.named.iter().for_each(|field| {
let name = &field.ident.clone().unwrap();
let ty = &field.ty;
quote!{
impl Foo {
pub set_bar(&mut self, v: #ty) {
self.bar = Some(v);
}
}
};
});
}
_ => {}
},
_ => panic!("You can derive it only from struct"),
}