Function syn::parse2

pub fn parse2<T: Parse>(tokens: TokenStream) -> Result<T>

Available on crate feature parsing only.

Parse a proc-macro2 token stream into the chosen syntax tree node.

This function will check that the input is fully parsed. If there are any unparsed tokens at the end of the stream, an error is returned.

This function parses a proc_macro2::TokenStream which is commonly useful when the input comes from a node of the Syn syntax tree, for example the body tokens of a Macro node. When in a procedural macro parsing the proc_macro::TokenStream provided by the compiler, use syn::parse instead.

This function is available only if Syn is built with the "parsing" feature.

Examples found in repository

src/item.rs (line 1458)

    fn pop_variadic(args: &mut Punctuated<FnArg, Token![,]>) -> Option<Variadic> {
        let trailing_punct = args.trailing_punct();

        let last = match args.last_mut()? {
            FnArg::Typed(last) => last,
            _ => return None,
        };

        let ty = match last.ty.as_ref() {
            Type::Verbatim(ty) => ty,
            _ => return None,
        };

        let mut variadic = Variadic {
            attrs: Vec::new(),
            dots: parse2(ty.clone()).ok()?,
        };

        if let Pat::Verbatim(pat) = last.pat.as_ref() {
            if pat.to_string() == "..." && !trailing_punct {
                variadic.attrs = mem::replace(&mut last.attrs, Vec::new());
                args.pop();
            }
        }

        Some(variadic)
    }