program volatile_doctest use stringifor_string_t type(string) :: astring type(string) :: anotherstring type(string) :: yetanotherstring logical :: test_passed(1) astring = 'Hello ' anotherstring = 'Bye bye' yetanotherstring = astring.cat.anotherstring test_passed(1) = yetanotherstring%chars()=='Hello Bye bye' print '(L1)', all(test_passed) endprogram volatile_doctest