Doug Gregor wrote:
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I think variadic templates are a big step forward for C++ libraries that deal with function objects, forwarding, and type-lists. If you're interested, please read the documentation, hack some code with the compiler, and tell your local C++ committee representative to vote for variadic templates in C++0x :)
I have tried out the compiler using the cygwin compiled code supplied. I have implemented the printf example. I had a name clash with the printf in the system, and renamed the local one printff. The return in the recursion had to be modified: /*return*/ printf(++s, args...); return; When I added this example: const char* more = "have nothing to do with the case %s %s\n"; printff(more, "tra la"); the output is have nothing to do with the case tra la tra la instead of an exception for an extra format. I hope this helps. Source code of example attached. John // printex.cpp // Variadic printf example from the manual. #include <iostream> #include <stdexcept> void printff(const char* s) { while (*s) { if (*s == '%' && *++s != '%') throw std::runtime_error("invalid format string: missing arguments"); std::cout << *s++; } } template<typename T, typename... Args> void printff(const char* s, const T& value, const Args&... args) { while (*s) { if (*s == '%' && *++s != '%') { std::cout << value; /*return*/ printf(++s, args...); return; } std::cout << *s++; } throw std::runtime_error("extra arguments provided to printff"); } int main() { try { const char* msg = "The value of %s is about %g (unless you live in %s).\n"; const char* another = "The flowers that bloom in the spring %s \n"; const char* more = "have nothing to do with the case %s %s\n"; printff(msg, std::string("pi"), 3.14159, "Indiana"); printff(another, "tra la"); printff(more, "tra la"); } catch(std::runtime_error s) { std::cout << "Caught " << s.what() << std::endl; } return 0; }