Function mint_struct

Mint a valid instance of a NAMED generated struct, recursing into its fields (depth-capped so recursion terminates: at the cap this returns `None`, which an enclosing unbounded collection absorbs by minting empty — loudly — while any other enclosing mint gets the caller's loud skip).

(
    types: &IntermediateTypes,
    ident: &crate::intermediate::RustIdent,
    depth: u8,
)