Dear Intel Fortran Compiler for Linux and Mac OS X users and developers,
I think that I found a number of issues when overloading "generic :: operator(-)" on a base derived data type -- let's call it A -- and calling the corresponding bindings with instances of a derived data type which extends A, --let's call it B--. The different scenarios tested were gathered in five programs attached to this post: test1.f90, test2.f90, test3.f90, test4.f90, and test5.f90. The outcome was as follows:
- test1.f90 compiles and generates the output that I would expect (OK).
amartin@Aetos:~/pruebas_fortran_03$ ifort test1.f90
amartin@Aetos:~/pruebas_fortran_03$ ./a.out
2.000000
2.000000
- test2.f90 compiles but it DOES NOT provide the output that I would expect (I believe the expected output should be the same as the one provided by test1.f90) (NO-OK).
amartin@Aetos:~/pruebas_fortran_03$ ifort test2.f90
amartin@Aetos:~/pruebas_fortran_03$ ./a.out
2.000000
- test3.f90 compiles but and generates the output that I would expect (OK).
amartin@Aetos:~/pruebas_fortran_03$ ifort test3.f90
amartin@Aetos:~/pruebas_fortran_03$ ./a.out
1.000000
- test4.f90 DOES NOT compile, and I believe that it should compile (NO-OK).
amartin@Aetos:~/pruebas_fortran_03$ ifort test4.f90
test4.f90(46): error #6355: This binary operation is invalid for this data type. [B_INSTANCE]
write(*,*) B_instance-B_instance
-------------^
test4.f90(46): error #6355: This binary operation is invalid for this data type. [B_INSTANCE]
write(*,*) B_instance-B_instance
------------------------^
test4.f90(46): error #6549: An arithmetic or LOGICAL type is required in this context.
write(*,*) B_instance-B_instance
-----------------------^
compilation aborted for test4.f90 (code 1)
- test5.f90 compiles and generates the output that I would expect (OK).
amartin@Aetos:~/pruebas_fortran_03$ ifort test5.f90
amartin@Aetos:~/pruebas_fortran_03$ ./a.out
1.000000
1.000000
If you take a careful look at the code snippets, you may observe that the NO-OK tests are the ones where the "generic :: operator(-)" is overloaded for both the unary and binary minus operator.
Could you please help me and determine whether the codes are standard compliant, and confirm that they should provide the outputs that I except? In case I am correct, is there any compiler-related issue? Can it be work-arounded? Should it be fixed?
I got the same behaviour with both the 15.0.2 and 16.0.0 compiler versions.With the GNU gfortran compiler (5.1.0) all tests compiled and generated the output that I would expect.
Many thanks in advance for your help.
