program volatile_doctest use stringifor_string_t type(string) :: astring logical :: test_passed(4) astring = 'Hello WorLD!' test_passed(1) = astring%start_with(prefix='Hello').eqv..true. test_passed(2) = astring%start_with(prefix='hell').eqv..false. test_passed(3) = astring%start_with(prefix='llo Wor', start=3).eqv..true. test_passed(4) = astring%start_with(prefix='lo W', start=4, end=7).eqv..true. print '(L1)', all(test_passed) endprogram volatile_doctest