Detection vector space automatic allocation strategy

Read the "STL source analysis" can know that vector space automatic allocation strategy is the space doubling.
Because the STL version is more, for the common two do under detection, vs2012 and GCC 5.3.0
Size (): Gets the current usage size
Capacity (): Gets the current container size

Allocate 1 million times to check.
Code

#include <vector>
#include <iostream>

void Vectortest ()
{
    std::vector<int> vTest ;
    for (int i = 0; i < 1000000; ++i)
    {
        vtest.push_back (1);
        int nSize = Vtest.size ();
        int ncapacity = Vtest.capacity ();
        if (nSize = = ncapacity)
        {
            std::cout<<nsize<< "\ T" <<nCapacity<<std::endl;
        }
    }
    std::cout<<std::endl;
};

Experimental results:
vs2012 each new 1/2 of the current space

g++ 5.3.0 each time the current space size is added, that is, the multiplier