https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64138
--- Comment #7 from Dominique d'Humieres <dominiq at lps dot ens.fr> --- I was sure to have seen discussions about such issues: pr33997 and https://groups.google.com/forum/#!msg/comp.lang.fortran/GIcxE7GM1ek/aP7eJpQ-T7QJ AFAIU the discussions, the relevant point for this PR is > (b) A nonoptional non-passed-object dummy argument whose name > is such that either the other procedure has no dummy argument > with that name or the dummy argument with that name is distinguishable > with it. Along this line I have renamed num to num1 and z1 to z2 in c_sub_rc module complex_number_module implicit none integer, parameter :: loc_real_precision = 8 type complex_number real(kind=loc_real_precision) :: real_part, imag_part end type complex_number interface c_sub module procedure c_sub_cc, & ! z1 - z2 c_sub_cr, & ! z1 - num, where num is a real number c_sub_rc ! num - z1, where num is a real number end interface contains ! -------------------------------------------------------------------------- type (complex_number) function c_sub_cc (z1, z2) type (complex_number), intent(in) :: z1, z2 c_sub_cc%real_part = z1%real_part - z2%real_part c_sub_cc%imag_part = z1%imag_part - z2%imag_part end function c_sub_cc ! -------------------------------------------------------------------------- type (complex_number) function c_sub_cr (z1, num) type (complex_number), intent(in) :: z1 real(kind=loc_real_precision), intent(in) :: num c_sub_cr%real_part = z1%real_part - num c_sub_cr%imag_part = z1%imag_part end function c_sub_cr ! -------------------------------------------------------------------------- type (complex_number) function c_sub_rc (num1, z2) type (complex_number), intent(in) :: z2 real(kind=loc_real_precision), intent(in) :: num1 c_sub_rc%real_part = num1 - z2%real_part c_sub_rc%imag_part = - z2%imag_part end function c_sub_rc end module complex_number_module program foo use complex_number_module type(complex_number) a, b real(loc_real_precision) x a%real_part = 1 a%imag_part = 2 x = 3 b = c_sub(a, x); print '(A,2F5.1)', 'a-x = ', b%real_part, b%imag_part b = c_sub(x, a); print '(A,2F5.1)', 'x-a = ', b%real_part, b%imag_part b = c_sub(z1=a, num=x); print '(A,2F5.1)', 'a-x = ', b%real_part, b%imag_part b = c_sub(num=x,z1=a); print '(A,2F5.1)', 'a-x = ', b%real_part, b%imag_part b = c_sub(num1=x,z2=a); print '(A,2F5.1)', 'x-a = ', b%real_part, b%imag_part end program foo This made the code to compile and if I am not mistaken to produce the correct result a-x = -2.0 2.0 x-a = 2.0 -2.0 a-x = -2.0 2.0 a-x = -2.0 2.0 x-a = 2.0 -2.0 Out of curiosity why do want to handle complex numbers through types while they are perfectly handled in Fortran by kinds? To conclude I think this PR should be closed as INVALID.
