How to CastTo properly ?

My class was derived from IGH_Goo.

public bool CastTo<T>(out T target)
{
           if (typeof(T).IsAssignableFrom(typeof(int))) {
               object ptr = this.data;
               target = (T)ptr;
               return true;
           }
         return false; // <- error
}

Throws this error.

Error : The Out Parameter must be assigned before control leaves the current method.

Older IGH_Goo interface has CastTo<T>(ref T target) instead of out.

Replies to This Discussion

Permalink Reply by emlplsn on March 17, 2014 at 3:43pm

If the method doesn't end up in your if-statement the variable "target" will never be assigned. This is a requirement when using out-parameters. Setting "target" to null in an else-scope might be working. Something like this:

public bool CastTo<T>(out T target)
{
           if (typeof(T).IsAssignableFrom(typeof(int))) {
               object ptr = this.data;
               target = (T)ptr;
               return true;
           }

else{

target = null;

return false; // <- error

}

Permalink Reply by David Rutten on March 19, 2014 at 9:13am