//-------------------------------------------------------------------
// Test.cpp
//-------------------------------------------------------------------

#include <stream.h>
#include "Pointer_2.h"

// Something "interesting" to point to...

struct Node
{
    int data;
    Pointer<Node> next;
};

// Pointer<T> can be passed by value and by reference

void Something (Pointer<int> pv, Pointer<int>& pr)
{
    pr = pv;
}

// Let's try some things!

int main ()
{
    Pointer<int> p1 = 0;
    Pointer<int> p2 = p1, p3;
    Pointer<Node> q1, q2;
    int *bad;

    if (p1 == p2)
    {
	cout << "No surprise: p1 == p2\n\n";
    }
    
    bad = new int;
    *bad = 49;
    cout << "*bad = " << *bad << "\n\n";

    // No compile-time or run-time error here, but you can't
    // dereference p1 or you'll get an error (see next comment)
    
    p1 = bad;
    
    // Run-time error dereferencing dangling pointer

//    cout << "*p1 = " << *p1 << "\n";

    // Compile-time error for mixed-mode assignment
    
//     bad = p1;
    
    New (p1);
    New (p2);
    p3 = p1;

    *p1 = 17;
    *p2 = -32;

    // Should see 17, -32, 17

    cout << "*p1 = " << *p1 << "\n";
    cout << "*p2 = " << *p2 << "\n";
    cout << "*p3 = " << *p3 << "\n\n";

    // Same as p3 = p2
    
    Something (p2, p3);
    
    // Should see 17, -32, -32

    cout << "*p1 = " << *p1 << "\n";
    cout << "*p2 = " << *p2 << "\n";
    cout << "*p3 = " << *p3 << "\n\n";

    p3 = p1;
    Delete (p1);
    if (p1 == 0)
    {
	cout << "Surprise: p1 == 0\n\n";
    }

    // Compile-time error for mixed-mode testing

//     if (p2 == 48600)
//     {
// 	cout << "Surprise: p1 == 48600\n\n";
//     }
    
    // Compile-time error for mixed-mode testing

//     if (p2 != 48600)
//     {
// 	cout << "Surprise: p1 == 48600\n\n";
//     }
    
    p1 = 0;
    if (p1 == 0)
    {
	cout << "No surprise: p1 == 0\n\n";
    }

    // Run-time error dereferencing null pointer

//     cout << "*p1 = " << *p1 << "\n";

    New (p1);
    *p1 = *p2 + 33;

    // Should see 1, -32

    cout << "*p1 = " << *p1 << "\n";
    cout << "*p2 = " << *p2 << "\n";

    // Run-time error dereferencing dangling  pointer
    
//     cout << "*p3 = " << *p3 << "\n\n";

    New (p3);

    // Memory leak caused here, but not reported until later
    
    p2 = p1;

    // Should see 1, 1, then some arbitrary value, but no error

    cout << "*p1 = " << *p1 << "\n";
    cout << "*p2 = " << *p2 << "\n";
    cout << "*p3 = " << *p3 << "\n\n";

    Delete (p1);

    // Run-time error deleting dangling pointer, with line number and
    // file name in error message

//     Delete (p2);

    // Compile-time error assigning non-null
    
//     p1 = 5745646;

    New (q1);
    q1->data = *p3;
    New (q1->next);
    q2 = q1->next;
    q2->data = 13;
    q2->next = 0;

    cout << "*q1 = " << "(" << q1->data << " (" << q1->next->data
	 << "))\n";
    cout << "q2->data = " << "(" << q2->data << ")\n\n";

    // Memory leak caused here, but not reported until later
    
    q1 = q1->next;

    Delete (q2);
    
    // Compile-time error for mixed-mode assignment

//     p1 = q1;

    // Compile-time error for mixed-mode test

//     if (p1 == q1)
//     {
// 	cout << "Surprise: p1 == q1\n\n";
//     }	

    // All memory leaks reported here

    Report_Storage_Allocation ();
}