C / C++ / MFC

//class CTest
CInner** mGetPt(void) {
	return &pt;
}

//_tmain()
*obj->mGetPt() = new CInner();

class CInner {
	public:
		CInner() : mx(1) { } //This is an initialiser list, and is equivalent to "mx = 1". This is quicker and cleaner than using "mx = 1"
		int GetMX() { return mx; }
		void SetMX(int nNewMx) { mx = nNewMx; } //This allows you to validate the value getting set, and is good style even if you don't need to validate it

	private:
		int mx; //It is good style to have variables as private, or protected, then have a get/set function which can validate the value
};

//Preallocate solution
class CTest {
	public:
		CTest() : pt(new CInner) { } //Allocate in the constructor
		~CTest() {
			if (pt != NULL) {
				delete pt; //Don't forget to delete the memory
			}
		}
		CInner *mGetPt() { return pt; } //Don't return by reference, it is bad style

	private:
		CInner *pt;
};

//Allocate on demand solution
class CTest {
	public:
		CTest() : pt(NULL) { } //Set to NULL
		~CTest() {
			if (pt != NULL) {
				delete pt; //Don't forget to delete the memory
			}
		}
		CInner *mGetPt() { //Don't return by reference, it is bad style
			if (pt == NULL) {
				pt = new CInner;
			}
			return pt;
		}

	private:
		CInner *pt;
};

int _tmain(int argc, TCHAR *argv[]) {
	CTest *obj = new CTest();
	cout << obj->mGetPt()->GetMX();
	cin.get();
	return 0;
}

//Base.h
class Base {
};

//Sub1.h
#include "Base.h"
class Sub1 : public Base {
};

//Sub2.h
#include "Base.h"
class Sub2 : public Base {
};

//Main.cpp
#include "Sub1.h"
#include "Sub2.h"

int main() {
	Sub1 s1;
	Sub2 s2;
	//do stuff with the classes
	return 0;
}

// File A.h
#define MY_GUARD_A_H

class A {
  // ...
};
// end of file A.h


// File A.cpp
#ifndef MY_GUARD_A_H
#include "A.h"
#endif

// ...

//end of file A.cpp

Andrew Brock wrote:

it would be rather silly to not do it that way

// file A.h

class A {
  // ...
};
// end f file A.h

// file B.h
#include "A.h"

class B : public A {
  // ...
};
// end of file B.h

// file B.cpp
#include "B.h"
#include "A.h"

// ...

// end of file B.cpp

void CustomPrintDlg::OnLandscapeChecked()
{
      // set the current Devmode to landscape
      LPDEVMODE pDevMode = GetDevMode();
      pDevMode->dmOrientation = DMORIENT_LANDSCAPE;
      GlobalUnlock(pDevMode);
}

typedef struct {
	wchar_t szCol1[4];
	whcar_t szCol2[4];
} DatabaseRow;

DatabaseRow drTable[2] = {
	{ L"row", L"one" },
	{ L"row", L"two" }
};

typedef struct {
	DWORD nFieldLen;
	BYTE pFieldData[]; //Note: this is a 0 sized array and may generate a compiler warning. It is perfectly safe if you use it correctly
} DatabaseField;

typedef struct {
	DWORD nColumns;
	DatabaseField *pColumns[]; //Another 0 sized array
} DatabaseRow;
//Allocate some memory for the table
int nColumns = 3;
DatabaseRow *pRow = (DatabaseRow *)malloc(sizeof(DatabaseRow) + sizeof(DatabaseField) * nColumns); //This is where the 0 sized array is useful, only the size of nColumns is counted in sizeof(DatabaseRow)