program volatile_doctest use stringifor_string_t type(string) :: astring type(string) :: anotherstring logical :: test_passed(2) astring = ' one ' anotherstring = 'two' test_passed(1) = ((astring/=anotherstring).eqv..true.) astring = 'the same ' anotherstring = 'the same ' test_passed(2) = ((astring/=anotherstring).eqv..false.) print '(L1)', all(test_passed) endprogram volatile_doctest