sig
type ('src, 'dst) t = ('src, 'dst) Blit.blito
val string_string : (string, string) Make_substring.??.t
val bigstring_string :
(Make_substring.bigstring, string) Make_substring.??.t
val string_bigstring :
(string, Make_substring.bigstring) Make_substring.??.t
val bigstring_bigstring :
(Make_substring.bigstring, Make_substring.bigstring) Make_substring.??.t
end