Explicitly mention Expr::* variants require "full"
@@ -15,7 +15,7 @@ ast_enum_of_structs! {
/// A Rust expression.
///
/// *This type is available if Syn is built with the `"derive"` or `"full"`
- /// feature.*
+ /// feature, but most of the variants are not available unless "full" is enabled.*
///
/// # Syntax tree enums
///
