// template3.cpp			By: Aiman Hanna -  ©1993-2006 Aiman Hanna

// The program illustrates how the ambiguity issue is still present when 
// working with template functions. This program simply DOES NOT WORK. Why?
//
//	Key Points: 	1) template functions & ambiguity (ambiguous calls). 

#include <iostream.h>

// template functions that has one formal type, called "Type". The function 
// expects two parameters of type "Type". The function finds and returns the 
// smaller value of the two passed values. Hence, the return type of the 
// template function is also "Type" as well. 

template <class Type>
Type  min( Type a, Type b )
{
 return a < b ? a : b;		// same as:  if ( a < b ) return a; else return b;
}




int main( )
{
 int x = 10, y = 5;
 double w = 13.2, z = 21.9;
 char ch1 = 'f', ch2 = 'k';

 cout << " The minimum value of the two integers x and y is: " << min( x, y ) 
 							             << endl << endl;
 cout << " The minimum value of the two doubles w and z is: " << min( w, z ) 
 							             << endl << endl;
 cout << " The minimum value of the two characters ch1 and ch2 is: " 
							<< min(ch1, ch2) << endl << endl;

// The following statement produces an ambiguous call to the template function
  cout << " The minimum value of the integer x and the double w is: " 
								<< min(x, w) << endl << endl;			// This is line 39

return 0;
}

// The result of compiling the program 
// On UNIX
/*
CC: "template3.cpp", line 39: error: use of template function min() does not match any of its template definitions (1806)
CC: "template3.cpp", line 39: error: ambiguous call:  ostream* -> operator <<(any ) (1736)
CC: "template3.cpp", line 39: choice of ostream::operator <<()s:
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(char );
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(unsigned char );
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(const char *);
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(int );
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(long );
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(double );
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(float );
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(unsigned int );
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(unsigned long );
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(void *);
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(streambuf*);
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(short );
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(unsigned short );
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(ostream&(*)(ostream&));
CC: "template3.cpp", line 39:   ostream& ostream::operator <<(ios&(*)(ios&));
CC: "template3.cpp", line 39: error: bad argument 1 type for ostream::operator <<(): any  (ios&(*)(ios&) expected) (1264)
CC: "template3.cpp", line 39: error: function operand for << (1425)
CC: "template3.cpp", line 39: error: function operand for << (1425)
CC: "template3.cpp", line 39: error: function operand for << (1425)
CC: "template3.cpp", line 39: error: function << ostream&(ostream&) (1420)
*/

// On Windows (VC++)
/*
Compiling...
template3.cpp
template3.cpp(39) : error C2782: 'template-parameter-1 __cdecl min(template-parameter-1,template-parameter-1)' : template parameter 'Type' is ambiguous
                                                                                                could be 'double'
                                                                                                or       'int'
Error executing cl.exe.

template1.exe - 1 error(s), 0 warning(s)

*/