Re: association of pointers

John Harper wrote:
In an attempt to understand pointers, I wrote the following:

PROGRAM testassoc3
INTEGER, TARGET :: beast = 666
INTEGER, POINTER :: ptr => NULL()
ALLOCATE(ptr)
ptr = beast
PRINT "(A,I4)",' After ptr = beast, ptr is',ptr
PRINT "(A,L2)",' associated(ptr,beast) is',associated(ptr,beast)
PRINT "(A,L2)",' associated(ptr) is',associated(ptr)
END PROGRAM testassoc3

The output from four different f95 compilers was

After ptr = beast, ptr is 666
associated(ptr,beast) is F
associated(ptr) is T

That appears to suggest that ptr was associated with something at the time of printing, but not with beast even though its value was that of beast. What was ptr associated with?
-- John Harper, School of Mathematics, Statistics and Computer Science, Victoria University, PO Box 600, Wellington 6140, New Zealand
e-mail john.harper@xxxxxxxxx phone (+64)(4)463 5341 fax (+64)(4)463 5045

Have you considered the differences between

ptr => beast

and

ptr = beast

?

-- mecej4
.

Relevant Pages

  • association of pointers
    ... INTEGER, TARGET:: beast = 666 ... PRINT "",' After ptr = beast, ptr is',ptr ... END PROGRAM testassoc3 ...
    (comp.lang.fortran)
  • Re: association of pointers
    ... John Harper wrote: ... INTEGER, TARGET:: beast = 666 ... That appears to suggest that ptr was associated with something at the time of printing, but not with beast even though its value was that of beast. ...
    (comp.lang.fortran)