stack overflow error in C++ program

Question

So i have this complex class , and i want to have an 2d array of complex numbers this is part of the code not all the code

class Complex {
public:
    /* con         


        

Answer 1

Any idea why?

Some compilers default the stack size to 1MB. You are allocating 65536 Complex objects that occupies 2 * sizeof(double) memory each. Assuming double to be 8 bytes (this information is implementation defined) you are effectively trying to allocate 16 * 65536 bytes (without considering possible paddings), which are 1048576 bytes, that causes the overflow.

An alternative is using dynamic allocation with a wrapper, that simulates a bi-dimensional array indexing, along the lines of this one:

template
class G {
private:
    std::unique_ptr mem;
public:
    G() : mem(new Complex[A * B]) {}
    Complex& operator()(std::size_t a, std::size_t b) {
        return mem[a * B + b];
    }
    Complex  operator()(std::size_t a, std::size_t b) const {
        return mem[a * B + b];
    }
};

Then you program simply becomes:

int main(int, char*[]) {
    G<256, 256> g;
    g(0, 0) = ...;
}

Of course you can generalize your wrapper G for a generic type with templates, but that's outside the scope of this answer.

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On a side note, you destructor:

~Complex() { r=0.0; i=0.0; }

is useless. Don't re-initialize memory that will be destroyed anyway when it leaves the scope.