#include <vector>
#include <stdio.h>
using namespace std;

#define DEBUG 0 

// type1 = double[12];
// type2 = type1[10000];

template<typename T, size_t T2>
struct vec {
    T body[T2];
    double & operator[](size_t elem) {
#if DEBUG
        if (elem >= T2) {
            throw ...;
        }
#endif
        return body[elem];
    }
};

#if 0
double x[12]; double y[12];
x = y; // Облом ???
vec<double,12> x; 
vec<double,12> y;
x = y; // Работает!

#endif

using d12 = vec<double,12>;

#if 0
struct d12 {
    vector<double> body;
    d12() {
        body.resize(12);
    }
    double & operator[](size_t elem) {
        return body[elem];
    }
};
#endif

class foo {
public:
    foo() {
        body.resize(10000);
    }
    d12 & operator[](size_t elem) {
        return body[elem];
    }
private:
    vector<d12> body;
};

int func(foo &f) {
    f[1][5]++;
    return f[1][5];
}

int main() {
    int cnt = 0;
    for (int i = 0; i < 10000; i++) {
        foo bar;
        cnt += func(bar);
    }
    printf("cnt=%d\n", cnt);
}