Re: Sorting two arrays with one call to sort()?

I compiled and run this using VS2003:

#include <iostream>
#include <algorithm>
#include <assert.h>

using namespace std;
const int N = 10;

template < typename tA, typename tB >
struct double_iterator {
    typedef double_iterator<tA,tB> self;
    tA* a;
    tB* b;
    int idx;
    double_iterator(tA* _a, tB* _b, int idx = 0) : idx(idx) {
            a = _a ;
            b = _b ;
    };

    struct value_type {
            tA a; tB b;
            tA *pa; tB *pb;
            value_type(tA *pa, tB *pb) : pa(pa), pb(pb), a(*pa),
b(*pb) {};
            void operator=(value_type other){
                    *pa = other.a; *pb = other.b;
            };
            bool operator<(value_type other){
                    return a < other.a ;
            };
    };

    typedef std::random_access_iterator_tag iterator_category;
    typedef int difference_type;
    typedef int distance_type;
    typedef value_type& reference;
    typedef value_type* pointer;

    value_type operator*(){ return value_type(a+idx,b+idx); }

    bool operator<(const self & other) const {
        assert( a == other.a && b == other.b );
        return idx < other.idx;
    }

    bool operator==(const self & other) const {
        return a == other.a && b == other.b && idx == other.idx;
    }
    bool operator!=(const self & other) const {
        return !(*this == other);
    }
    int operator-(const self & other) {
        return idx - other.idx;
    }
    self operator-(int to_del) const {
        self ret = *this;
        ret.idx -= to_del;
        return ret;
    }

    self operator++(int) {
        self temp = *this;
        ++idx;
        return temp;
    }
    self &operator++() {
        ++idx;
        return *this;
    }

    self operator--(int) {
        self temp = *this;
        --idx;
        return temp;
    }
    self &operator--() {
        --idx;
        return *this;
    }
};

template < typename tA, typename tB >
double_iterator<tA,tB> operator+(double_iterator<tA,tB> it, int
to_add) {
    it.idx += to_add;
    return it;
}

template < typename tA, typename tB >
double_iterator<tA,tB> operator+(int to_add, double_iterator<tA,tB>
it) {
    it.idx += to_add;
    return it;
}

int main(void){
        int A[N];
        float B[N];

        for (int i = 0; i < N; ++i){
         A[i] = rand(); B[i] = A[i] % 10;
         cout << "\t" << A[i] << "\t" << B[i] << endl;
        }

        std::sort(double_iterator<int,float>(A,B),
                  double_iterator<int,float>(A,B,N));

        for (int i = 0; i < N; ++i){
         cout << "\t" << A[i] << "\t" << B[i] << endl;
        }

        return 0;

}

Best,
John

--
http://John.Torjo.com -- C++ expert
.... call me only if you want things done right

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