We tell bindgen to generate newtypes for enums:

but Boring uses an anonymous enum for ERR_LIB_* constants:

https://github.com/google/boringssl/blob/5622da92e1e7bacb5d0785ff5650a5a23b143b84/include/openssl/err.h#L223-L224

so bindgen picks _bindgen_ty_1. I wanted to use the newtypes in an API, but referring to the type as _bindgen_ty_1 is fragile, because it could break if boringssl adds any other anonymous type, or bindgen finds one in system headers.

There's a bit of hacky parsing to find the actual type name of ERR_LIB_SSL's newtype (bindgen doesn't expose AST or anything like that). The newtype is pub used under a future-proof ErrLib name.