Re: Constraining the length of std::vector<double>
sean_in_raleigh@yahoo.com wrote:
On Jan 16, 9:19 am, Rune Allnor <all...@tele.ntnu.no> wrote:
I have an application where I need to do some computations on
vectors of numerical data. Specifically, the routine requires an
N-dimensional point and an N-dimensional vector as input.
[...]
It is no problem to do this at run-time and control parameters,
but this would imply a run-time overhead I would prefer
to avoid, if possible, and do all this book-keeping at
compile time instead.
How about something like this?
#include <vector>
using namespace std;
template<unsigned VectorSize>
class SizedDoubleVector : public vector<double>
{
public:
SizedDoubleVector() : vector<double>(VectorSize) {}
enum { size = VectorSize };
};
[snip]
Since you inherit publicly, methods like push_back() are still available.
Thus, you can change the length of the vector. Basically, the class is not
enforcing its invariant but requires flawless cooperation from the
programmer.
One could use private inheritance and make only those methods available that
do not change the length of the vector.
Best
Kai-Uwe Bux
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