on Thu Nov 01 2012, Marc Glisse <marc.glisse-AT-inria.fr> wrote:
On Thu, 1 Nov 2012, Dave Abrahams wrote:
on Wed Oct 31 2012, Antony Polukhin <antoshkka-AT-gmail.com> wrote:
May be it would be better to write a metafunction:
template <class T> size_forward { enum ENUM{value = sizeof(T)}; };
User is free to specialize it, so Boost.Variant can use it to get sizes of types (instead of directly calling to sizeof(T))
Specialization for your case will be:
template <> struct size_forward<vector<Y>> { enum ENUM{value = sizeof(vector<X>)}; };
I think that such metafunction could be widely used (for example in Boost.Optional)
As far as I can tell, putting sizeof() inside a layer of template instantiation doesn't solve anything. But maybe I'm missing something.
I think he is replacing sizeof(vector<incomplete>) with sizeof(vector<int>) (as suggested a few messages back), not just hiding sizeof in templates.
Yeah... problem is, that might turn out to be wrong. -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost