PR 58148 patch

[Paolo Carlini]

On 08/26/2013 09:44 PM, François Dumont wrote:
> Hi
>
>     The problem exposed in PR 58148 is quite trivial, std::common_type 
> cannot find a result when instantiated with char* and const wchar_t*. 
> The attached patch will fix this problem by dealing with a 
> std::common_type resolution failure even if the drawback is that 
> following call won't be detected as an invalid one anymore:
>
>   std::vector<int> v;
>   ....
>   v.insert(v.begin(), reinterpret_cast<char*>(v.data() + 1), 
> reinterpret_cast<char*>(v.data() + 5)); // Expected failure
For the time being I think we should simply live with this. To be 
honest, I think that at this level even the very idea of using 
common_type (and relying on the very recent sfinae-friendly feature) is 
a bit too much, I would just return true if the type of 
addressof(*__other) != container::pointer (modulo const). Thus have a 
__foreign_iterator_aux4 taking two container::const_pointer and a fall 
back always returning true.

Paolo.