Originally Posted by vijayan121

>
but there is good news. c++ programmers will never have to use the unsafe and error-prone <cstdarg> ; c++0x has a solution. using variadic templates, we can write a typesafe function taking an arbitrary number of arguments of arbitrary types. http://en.wikipedia.org/wiki/C++0x#Variadic_templates

here is how you would write largest_of a variable number of values in c++0x.

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#include <iostream>
#include <string>
// compile with gcc 4.3 with the -std=c++0x switch
 
template< typename T > inline 
const T& largest_of( const T& a, const T& b )
{ return a>b ? a : b ; }
 
template< typename T, typename ...REST > inline
const T& largest_of( const T& first, const REST&... rest... )
{ return largest_of( first, largest_of( rest... ) ) ; }
 
int main()
{
  std::cout << largest_of( 1, 9, 2, 8, 3, 7, 4, 6, 5 ) << '\n' ;
  std::cout << largest_of( 5.3, 8.9, -3.2, 17.8, 4.2, 7.0 ) 
          << '\n' ;
  const std::string s1("abc"), s2("2345"), 
                 s3("vufuk"), s4("ffyfyu") ;
  std::cout << largest_of( s1, s2, s3, s4 ) << '\n' ;
}
/**
>g++43 -Wall -std=c++0x -pedantic -Werror largest_of.cc && ./a.out
9
17.8
vufuk
*/

#include <iostream> #include <string> // compile with gcc 4.3 with the -std=c++0x switch template< typename T > inline const T& largest_of( const T& a, const T& b ) { return a>b ? a : b ; } template< typename T, typename ...REST > inline const T& largest_of( const T& first, const REST&... rest... ) { return largest_of( first, largest_of( rest... ) ) ; } int main() { std::cout << largest_of( 1, 9, 2, 8, 3, 7, 4, 6, 5 ) << '\n' ; std::cout << largest_of( 5.3, 8.9, -3.2, 17.8, 4.2, 7.0 ) << '\n' ; const std::string s1("abc"), s2("2345"), s3("vufuk"), s4("ffyfyu") ; std::cout << largest_of( s1, s2, s3, s4 ) << '\n' ; } /** >g++43 -Wall -std=c++0x -pedantic -Werror largest_of.cc && ./a.out 9 17.8 vufuk */

Originally Posted by vijayan121

> There are no compilers that support it
the output that i posted is with the code compiled by gcc 4.3 today; they are not my visualization of how it would look like in 2020.

Originally Posted by vijayan121

> we still have to resort to stdarg.h to get variable argument functions you may have to. i do not. even without gcc 4.3.