Suggestion: "fix" assert(obj)

[Ary Manzana]

What I meant was: if the compiler runs the invariants before and after 
each method call... when would you like to explicitly check the 
invariant using assert?

---
SomeObject o = new SomeObject;

// Here the invariant is called automaticaly
o.someMethod();
// Here the invariant is called automaticaly

assert(o); // what's the point? It was done just a second.
---

Unless... Unless you modify a field, and then call the invariant to 
check if everything is in place. But that's a smell of bad design.

Georg Wrede escribió:
> ((Reversing another top-post))
> 
> Ary Manzana wrote:
>> Kristian Kilpi escribió:
>>
>>> This issue has been proposed before. Well, I think it's the time 
>>> suggest it again...
>>>
>>> The problem is that
>>>
>>> assert(obj);
>>>
>>> does not first check if 'obj' is null. It just executes the
>>> object's invariants.
> 
>> Why would you want to check an object's invariant? Isn't the compiler
>> doing that before and after you execute a public method? What's the
>> use for it?
> 
> First: checking invariants is (most normally) a runtime excercise. 
> Normally the situations that lead to a risk of "breaking" the invariants 
> are due to circumstances the programmer didn't think of at first hand, 
> which naturally suggest a runtime check, usually with Real Use Case Data.