module Map_to_safe:sig..end
type'areader ='a Read_ml.reader
type('a, 'b)reader1 ='a Unsafe_read_c.reader -> 'b Read_ml.reader
type('a, 'b, 'c)reader2 ='a Unsafe_read_c.reader -> ('b, 'c) reader1
type('a, 'b, 'c, 'd)reader3 ='a Unsafe_read_c.reader -> ('b, 'c, 'd) reader2
type'awriter ='a Write_ml.writer
type('a, 'b)writer1 ='a Unsafe_write_c.writer -> 'b Write_ml.writer
type('a, 'b, 'c)writer2 ='a Unsafe_write_c.writer -> ('b, 'c) writer1
type('a, 'b, 'c, 'd)writer3 ='a Unsafe_write_c.writer -> ('b, 'c, 'd) writer2