// unnamespace-main-1-2.cpp		By: Aiman Hanna -  ©1993-2006 Aiman Hanna

// This program illustrates unnamed namespaces. 
// Sometimes, it is desired to define an object, a function, a class type, 
// or any other entity to be visible only to a small portion of the program; this 
// will consequently reduces the namespace pollution problem. Since the entity is 
// not going to be used outside this program (or a portion of it), it is better to 
// achieve this using a different method (using namespaces would be intended to 
// avoid collision with other similar names in other files, which is not the case here).
//  
// One way to limit the scope of an entity could be achieved by declaring the variable 
// inside a function (such as local variables for example). However, what if this entity
// is to be seen by multiple functions, without making this method visible to the 
// entire program? 
// In this case, unnamed namespaces can be used.     
// this program does not in fact show how unnamed namespaces can be used; rather why 
// they are (could be) needed. Notice that this program does NOT work. 

#include "unnamespace1.h"
#include "unnamespace2.h"



int main()
{
	fun1();
	fun2();
	fun3();
	fun4();
	fun5();
	fun6();
	fun7();
	fun8();
	cout << endl;
	return 0;
}

/* The result of compiling & linking the program
Compiling...
unnamespace-main-1-2.cpp
unnamespace1.cpp
unnamespace2.cpp
Linking...
unnamespace2.obj : error LNK2005: "void __cdecl greeting(void)" (?greeting@@YAXXZ) already defined in unnamespace1.obj
Debug/namespace-main-1-2.exe : fatal error LNK1169: one or more multiply defined symbols found
Error executing link.exe.

namespace-main-1-2.exe - 2 error(s), 0 warning(s)


*/