• Jason House <jason.james.house gmail.com> Sep 26 2009

Jason House <jason.james.house gmail.com> writes:

Walter Bright Wrote:

 Denis Koroskin wrote:
 One more:
 
 T foo(bool someCondition)
 {
     T? t;
     if (someCondition) t = someInitializer();
     // ...
 
     if (t.isNull) { // not initialized yet
         // ...
     }
 
     return enforce(t); // throws if t is not initialized yet, because 
 foo *must* return a valid value by a contract
 }


 It seems to me you've got null references there anyway?
 
 What would you do about:
 
     T[] a;
     a[i] = foo();
 
 where you want to have unused slots be null (or empty, or nothing)?


Your example segfaults. A is null.

If T is const or immutable, special care is also required.