Hello,
I was trying to understand user-defined derived type I/O, but had some weird issues. I stripped it down to this minimal example:
1 ! ============== !
2 ! === MODULE === !
3 ! ============== !
4
5 module SomeModule
6
7 implicit none
8
9 interface write(formatted)
10 module procedure WriteSomeType
11 end interface
12
13 type SomeType
14 integer :: value
15 end type
16
17 contains
18
19 subroutine WriteSomeType(var, unit, iotype, v_list, ios, iom)
20
21 class(SomeType), intent(in) :: var
22 integer , intent(in) :: unit
23 character(*) , intent(in) :: iotype
24 integer , intent(in) :: v_list(:)
25 integer , intent(out) :: ios
26 character(*) , intent(inout) :: iom
27
28 write(*,*) "DEBUG: using UDTIO"
29
30 write(unit, *, iostat=ios, iomsg=iom) var % value
31
32 end subroutine WriteSomeType
33
34 end module SomeModule
35
36 ! =============== !
37 ! === PROGRAM === !
38 ! =============== !
39
40 program SomeProgram
41
42 use SomeModule
43
44 implicit none
45
46 type(SomeType) :: var
47
48 var % value = 10
49
50 write(*,*) var
51
52 contains
53
54 !subroutine SomeSubroutine(arg)
55 !
56 ! type(SomeType) :: arg
57 !
58 ! write(*,*) arg
59 !
60 !end subroutine SomeSubroutine
61
62 end program SomeProgram
When I compile this with ifort 15.0.1 on CentOS 6 and run it, the output is
DEBUG: using UDTIO 10
indicating, that the the UDTIO subroutine has been used. When I uncomment SomeSubroutine and recompile, the output is
10
so just the usual output of derived types. I do not understand this - I don't even call SomeSubroutine?
Thanks,
Max
