Re: [boost] [review][constrained_value] ReviewofConstrainedValueLibrary begins today

Subject: Re: [boost] [review][constrained_value] ReviewofConstrainedValueLibrary begins today
From: Chris (indy271828_at_[hidden])
Date: 2008-12-07 18:37:06

Robert Kawulak wrote:
>> From: Robert Kawulak
>>     
>>> From: Chris
>>>  Or add something like this:
>>> class A {
>>>
>>> A() { // fails
>>> }
>>>
>>> must_initialize<int> t;
>>> };
>>>       
>> The problem is that the fact whether the default value is 
>> valid or not depends on the constraint used and this can't be 
>> verified at compile-time in most cases.
>>     
>
> This is even more tricky, because in some cases the error policy is able to
> adjust the value to make it constraint conforming. So should the default
> construction be disabled in such cases too or not?
>   
Sorry I did not clarify that there were no default template parameters. 
(no error policy)
must_initialize was not referring to any of your constrained classes.   
It was just a simple class to be added to your library if you wanted, 
that forces the user to initialize a variable.  That is the compile time 
constraint.

template <typename T>
class must_initialize
{
public:
    must_initialize(T t) : _value(t) { }
   // operater overloads here

private:
   must_initialize();
   T _value;
};

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