Re: How should unordered_map be used correctly ... ?

Ah thank you ... I guessed that already through your previous answer
so decided that maybe things would be easier for all of us ;-) if i
was actually finished my code ha ha ha... so here it is... it seems to
work. Let me know if you see anything that I am doing wrong (I mean I
know I use struct and all that which is not for the C++ purist but I
am just prototyping here to understand how unordered_map works. Thx a
lot for your feedbacks.

Thx =D6=F6 Tiib (not sure how to pronounce your name ;-)

-c

#include <cstdio>
#include <cmath>
#include <cstdlib>

#include <tr1/unordered_map>

//using namespace stdext;
//http://stackoverflow.com/questions/2099540/defining-custom-hash-
function-and-equality-function-for-unordered-map

template<typename T>
struct point {
    T x, y, z;
};

struct hashfunc {
    size_t operator() (const point<int> &pt) const { return 541 * pt.x
+ 79 * pt.y + 31 * pt.z; }
};

struct setequal {
    bool operator() (const point<int> &pa, const point<int> &pb) const
{ return (pa.x == pb.x && pa.y == pb.y && pa.z == pb.z); }
};

typedef struct voxel {
    float data;
};

typedef std::tr1::unordered_map<point<int>, voxel *, hashfunc,
setequal> tablegrid;

float signedrand() { return (drand48()-0.5)*2; }

int main (int argc, const char * argv[])
{
    int dim = 1;
    float cellsize = 0.01;
    //int gridsize = dim * dim * dim;
    //printf("grid size %d\n", gridsize);
    int npts = 1e6;
    tablegrid grid;
    point<int> pt;
    for (int i = 0; i < npts; ++i) {
        if (i%512==0) fprintf(stderr, "\b\b\b\b%d%c", int(100*i/
float(npts-1)), '%');
        pt.x = int(dim * signedrand() / cellsize);
        pt.y = int(dim * signedrand() / cellsize);
        pt.z = int(dim * signedrand() / cellsize);
        tablegrid::const_iterator it = grid.find(pt);
        if (it != grid.end()) {
            // do nothing
        }
        else {
            grid[pt] = new voxel;
        }
        //printf("val %d\n", hashfunc(pt));
    }
    printf("\nsize of table %d\n", grid.size());
    // delete mem
    tablegrid::const_iterator it = grid.begin();
    for (; it != grid.end(); ++it) {
        delete it->second;
    }
    printf("delete mem done\n", grid.size());
    return 0;
}