(module str_clone_cross_realisation
  (fn main
    (doc "Iter 24.1: cross-realisation invariant for str_clone. Clones a heap-Str (produced by int_to_str 42) AND a static-Str (literal `abc`); both clones produce fresh heap-Str slabs that print their input bytes. Pins the uniform-consumer-ABI claim — str_clone only reads the len-field at offset 0 plus the bytes plus the NUL; it never consults the (absent for static-Str) rc_header. RC stats under --alloc=rc: allocs == 3 (int_to_str output + two str_clone outputs), frees == 3, live == 0.")
    (type (fn-type (params) (ret (own (con Unit))) (effects IO)))
    (params)
    (body (let src_heap (app int_to_str 42) (let c1 (app str_clone src_heap) (let c2 (app str_clone "abc") (let _a (seq (do io/print_str c1) (do io/print_str "\n")) (seq (do io/print_str c2) (do io/print_str "\n")))))))))