Takes a tokenstream::TokenStream and returns a Vec<self::TokenTree>. Specifically, this
takes a generic TokenStream, such as is used in the rest of the compiler, and returns a
collection of TokenTree for use in parsing a macro.
Takes a tokenstream::TokenTree and returns a self::TokenTree. Specifically, this takes a
generic TokenTree, such as is used in the rest of the compiler, and returns a TokenTree
for use in parsing a macro.