Function TRUELENGTH_unchecked 

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

Get the true length (allocated capacity) of a vector.

May be larger than LENGTH for vectors with reserved space. ALTREP-aware. Unchecked FFI binding for TRUELENGTH. Generated from source location line 622, column 12. Generated from source file miniextendr-api/src/sys.rs.