hwr2023_b/CPlusPlus/intro/main.cpp

#include <iostream>
#include <Windows.h>
#include <memory>
#include "functions.h"
#include "ClassA.h"
#include "ClassB.h"

using namespace std;

void functionB() {}
void functionC();
void functionD(); // forward declaration

int main()
{
	//std::cout << "Hello World!" << std::endl;
	//cout << "Hallo" << endl;

	////functionA(); // compiler error, function is not declared, but defined afterwards
	//functionB(); // no error
	////functionC(); // linker error, function is declared, but not defined
	//functionD(); // no error
	////functionE(); // linker error, function is defined in header and included in two different source files
	//functionF(); // no error

	//short s = 0;
	//unsigned short us = 0;
	//int i = 0;
	//long l = 0;

	//cout << "sizeof short: " << sizeof(s) << endl;
	//cout << "sizeof int: " << sizeof(i) << endl;
	//cout << "sizeof long: " << sizeof(l) << endl;
	//cout << "sizeof long long: " << sizeof(long long) << endl;
	//cout << "sizeof bool: " << sizeof(bool) << endl;

	//BOOL b;

	//int number;
	//cin >> number;
	//cout << "number: " << number << endl;

	//char c;
	//cin >> c;
	//cout << "c: " << c << endl;

	//string str;
	//cin >> str;
	//cout << "str: " << str << endl;

	//char sz[128];
	//cin >> sz;
	//cout << "sz: " << sz << endl;
	//cin >> sz;
	//cout << "sz: " << sz << endl;

	//int numbers[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

	//cout << "print local array" << endl;
	//for (size_t i = 0; i < sizeof(numbers) / sizeof(int); i++)
	//{
	//	cout << numbers[i] << " ";
	//}
	//cout << endl;

	//cout << "print remote array" << endl;
	//printArray(numbers, size(numbers));

	//int n = 1;
	//changeInt(n);
	//cout << "n (" << &n << "): " << n << endl;
	//changeIntPointer(&n);
	//cout << "n (" << &n << "): " << n << endl;
	//changeIntReference(n);
	//cout << "n (" << &n << "): " << n << endl;

	//int* pNumber = nullptr;
	//int* pNumber2 = new int;
	//
	//if (pNumber2 != nullptr)
	//{
	//	delete pNumber2;
	//	pNumber2 = nullptr;
	//}

	//pNumber = new int;
	//*pNumber += 10;
	//pNumber = new int; // BAD - Memory Leak

	//unique_ptr<int> un = make_unique<int>(0);
	//*un = 100;
	//
	//shared_ptr<int> sn = make_shared<int>(0);
	//*sn = 10;
	//cout << "sn refs: " << sn.use_count() << endl;
	//shared_ptr<int> sn2 = sn;
	//cout << "sn refs: " << sn.use_count() << endl;
	//sn.reset();
	//cout << "sn refs: " << sn.use_count() << endl;
	//cout << "sn2 refs: " << sn2.use_count() << endl;

	//weak_ptr<int> wn = sn2;
	//if (!wn.expired())
	//{
	//	shared_ptr<int> ln = wn.lock();
	//	*ln = 1234;
	//	cout << "sn2 refs: " << sn2.use_count() << endl;
	//}
	//cout << "sn2 refs: " << sn2.use_count() << endl;

	//ClassA classA;
	//ClassA classA2 = classA;
	//ClassB classB;
	//int n = classA.GetNumber();
	//cout << n << endl;
	//classB.GetNumber();

	IPrintable* pPrintable = nullptr;
	pPrintable = new ClassB();
	//(*pPrintable).Print();
	//pPrintable->Print(); // same line as above, but simpler
	////ClassB* pClassB2 = (ClassB*)pPrintable; // C-Cast, CAUTION: DANGER!!!
	//ClassB* pClassB2 = dynamic_cast<ClassB*>(pPrintable); // c++ cast for polymorhpic cast
	//float f = 1.0f;
	//int i = static_cast<int>(f); // c++ cast, convert one static data type into another
	////int* nonsense = reinterpret_cast<int*>(pPrintable); // c++ cast like C-Cast, CAUTION: DANGER!!!
	//const char csz[13] = "Hello World";
	//char* sz = const_cast<char*>(csz);

	// What's the difference?
	//const int* cip;
	//int const* icp;
	//int* const ipc;
	//const int const* cicp;
	//const int* const cipc;
	//int const* const icpc;
	//const int const* const cicpc;

	//delete pPrintable;
	//pPrintable = nullptr;
	safeDelete(pPrintable);

	return 0;
}

void functionA() {}

void functionD() {}