variadic-functions

I have a c++ function taking variable number of arguments. char const* Fun(int num, ...) { ....//does some processing on the arguments passed } Boost Python code for exposing this function is written as, using namespace boost::python; BOOST_PYTHON_MODULE( lib_boost ) { def( "Fun", Fun ); } while compiling this code gives the below error In file included from /boost_1_42_0/boost/python/data_members.hpp:15, from /boost_1_42_0/boost/python/class.hpp:17, from /boost_1_42_0/boost/python.hpp:18, from Lib_boost.h:3, from Lib_boost.cpp:1: /boost_1_42_0/boost/python/make_function.hpp: In function

I need a way to pass a variable amount of parameters to a function in this circumstance: template<typename ...T> struct Lunch { Lunch(T...){} }; template<typename T> T CheckLuaValue(lua_State* luaState,int index) { //Do Stuff return value; } template <class MemberType, typename ReturnType, typename... Params> struct MemberFunctionWrapper <ReturnType (MemberType::*) (Params...)> { static int CFunctionWrapper (lua_State* luaState) { ReturnType (MemberType::*)(Params...) functionPointer = GetFunctionPointer(); MemberType* member = GetMemberPointer(); int index = 1; //Get a value for each type in

I just happened to have similar situation like in this question from two years: Variadic function (va_arg) doesn't work with float? There is said that the problem is promoting float to double when we call things like va_arg(arg, float) My question is at the end of this post, but first let's take a look at @Jack's answer below the question linked above: #include <stdio.h> #include <stdarg.h> void foo(int n, ...) { va_list vl; va_start(vl, n); int c; double val; for(c = 0; c < n; c++) { val = va_arg(vl, double); printf("%f\n", val); } va_end(vl); } int main(void) { foo(2, 3.3f, 4.4f); return 0;

In a function like printf, we use stdarg.h to handle the variadic parameters. void print(int args,...){ va_list ap; va_start(ap, args); int i = 0; for(i=0; i<args; i++){ printf("%d\n",va_arg(ap, int)); } va_end(ap); } We want to parse the format list (the first argument given to our variadic function) to track the types of the arguments specified in the format list then, call va_arg with the appropriate type. I make a first loop to parse the format list, store the specifiers letters into an array. So I know which type we expect and how many there is. ex: ft_like_printf("Watch your %d %s\n", 6,

I using va_list like this: void foo(const char* firstArg, ...) { va_list args; va_start (args, firstArg); for (const char* arg = firstArg; arg != NULL; arg = va_arg(arg, const char*)) { // do something with arg } va_end(args); } foo("123", "234", "345") the first three arguments was passed to foo correctly, but where "345" is done, arg = va_arg(arg, const char*) set some other freak value to arg . so What's the problem. I using llvm3.0 as my compiler. C does not automatically put a NULL at the end of a ... argument list. If you want to use NULL to detect the end of the arguments, you must pass

Why does varargs have to be the last parameter in method signature? I want to know the reason. Because it makes the compiler's life simpler. There's no real reason why it couldn't have more arguments after, but it would require a much more complex compiler and so the spec was written that way. The main reason is because it would be potentially ambiguous otherwise.... For example, how could the compiler tell whether arguments are varargs or separate named arguments in a long list of arguments with multple varargs? Imagine a method signature like: printNames(String... girls, String... boys); If