Re: Using different header files and selecting conditionally

I have two header files with almost identical information. These
header files represents different versions of a data feed

When i am processing a feed, i need to choose in runtime which
structs from which header file to use. I have been thinking of
using namespaces:

**file ver1 and ver2**
struct mystruct {
  int i;} t;

**EOF**

namespace ver_1
{
  #include "ver1.hpp";
}

namespace ver_2
{
  #include "ver2.hpp";
}

void test()
{
  if(useNew)
    using namespace ver_1;
  else
    using namespace ver_2;

  t.i = 5;
}

This wont work, since conditional namespace is not valid. What
is the best way of doing this? Bear in mind that in the
future, new versions may appear, so creating a test() for each
is not an option