Can I use value_type on an instance of the vector, not on its type

Question

while playing and trying to calculate total size of vector I tried something like

vector<double> vd;
auto area = vd.size()* sizeof (vd::value_type); 
//Ive seen Stepanov use area as name for this kind of size, idk if he adds the sizeof vd also to area :)

Unfortunately this doesnt work... I need to use vector<double>::value_type but that makes code less readable. Can it be made to work? I dont like sizeof vd.front() because it just looks ugly to write front() for this.
EDIT: decltype variants also fit in what I would call ugly category...

Answer 1

I think decltype can be used:

auto area = vd.size() * sizeof(decltype(vd)::value_type);

as you are using auto I assume C++11 is permitted.

Confirmed with g++ v4.7.2 and clang v3.3.