Function Rf_xlength_unchecked 

pub(crate) unsafe extern "C-unwind" fn Rf_xlength_unchecked(
    x: SEXP,
) -> R_xlen_t

Unchecked FFI binding for Rf_xlength. Generated from source location line 1973, column 19. Generated from source file miniextendr-api/src/ffi.rs.