Re: [Boost-users] boost::sub_range vs boost::iterator_range

From: Thorsten Ottosen (tottosen_at_[hidden])
Date: 2005-12-09 16:42:35

MB wrote:
> Thorsten Ottosen wrote:
> 
>>Victor A. Wagner Jr. wrote:
>>
>> >> Seems to me that sub_range is a convenience class to describe 
>>iterator ranges from ranges or containers that model ForwardRange, from 
>>which you can propagate constness.
>> >
>> >
>> >
>> > yup, that's what I thought also
>>
>>
>>It seems that the problem was caused by the fact that the vc71
>>generates default operators a bit wierd.
>>  The copy-constructor is default generated and so does simply copy the 
>>iterators. It seems that the default generated constructor/ assignment 
>>for sub_range calls a templated version of iterator_range's 
>>construcgtor/ assignment operator
>>
>>I think this might be a bug in the compiler.
> 
> 
> I thought it was intentional.
> See:
> 
> void test()
> {
>    std::string str;
> 
>    // hey, const sub_range.
>    const boost::sub_range<std::string> rng1(str);
> 
>    // whether or not to allow...?
>    boost::sub_range<std::string> rng2 = rng1;
> }
> 
> I don't know the answer for sure.

Can you assing a const vector<T> to a mutable vector<T>?

-Thorsten