Output variables that are conditionally available

[rmcd-mscb]

@mdpiper There are some variables that are conditionally allocated. After talking with Parker I think I'm going to just take them out of the BMI. However for the sake of argument would something like this work fine in a bmi function?

      case('gw_upslope')
        if(this%model%control_data%cascadegw_flag%value > 0) then !Mark will this conditional work here?
            size = sizeof(this%model%model_simulation%groundwater%gw_upslope(1)) 
            bmi_status = BMI_SUCCESS
        else
            size = -1
            bmi_status = BMI_FAILURE
        endif

[mdpiper]

Definitely! Or you could use allocated().

[rmcd-mscb]

Thanks Mark, I'm adding @pnorton-usgs for the sake of conversation. In this case gw_upslope does not have the allocatable attribute so allocated() doesn't work. so using cascadegw_flag would be the test.

Aside: The cascade module is not implemented in PRMS6 yet and Parker suggests removing vars associated with the cascade module for now and perhaps that's the best solution. However if the cascade module is implemented we'd still need conditional to return the value.

Regardless of the aside - I'm wondering, fully acknowledging my Fortran limitations, if gw_upslope, and others like it should have an allocatable attribute? Intel's take is that unless a var needs to be represented as just a pointer, if the var can use ALLOCATABLE it should (https://software.intel.com/en-us/forums/intel-fortran-compiler/topic/276711). If I'm off base here I'm sorry and apologize for taking your time :)