variadic

I was playing around with variadic templates (gcc 4.5) and hit this problem : template <typename... Args> boost::tuple<Args...> my_make_tuple(Args... args) { return boost::tuple<Args...>(args...); } int main (void) { boost::tuple<int, char> t = my_make_tuple(8, 'c'); } GCC error message : sorry, unimplemented: cannot expand 'Arg ...' into a fixed-length argument list In function 'int my_make_tuple(Arg ...)' If I replace every occurrence of boost::tuple by std::tuple , it compiles fine. Is there a problem in boost tuple implementation? Or is this a gcc bug ? I must stick with Boost.Tuple for

is it possible to construct variadic arguments for function by overloading operator comma of the argument? i want to see an example how to do so.., maybe something like this: template <typename T> class ArgList { public: ArgList(const T& a); ArgList<T>& operator,(const T& a,const T& b); } //declaration void myFunction(ArgList<int> list); //in use: myFunction(1,2,3,4); //or maybe: myFunction(ArgList<int>(1),2,3,4); It is sort-of possible, but the usage won't look very nice. For exxample: #include <vector> #include <iostream> #include <algorithm> #include <iterator> template <class T> class list

The uncurry function only works for functions taking two arguments: uncurry :: (a -> b -> c) -> (a, b) -> c If I want to uncurry functions with an arbitrary number of arguments, I could just write separate functions: uncurry2 f (a, b) = f a b uncurry3 f (a, b, c) = f a b c uncurry4 f (a, b, c, d) = f a b c d uncurry5 f (a, b, c, d, e) = f a b c d e But this gets tedious quickly. Is there any way to generalize this, so I only have to write one function? Try uncurryN from the tuple package. Like all forms of overloading, it's implemented using type classes. In this case by manually spelling out

I'm building a Redis Module in Rust. I've found some good examples, but I'm stuck when dealing with interfacing a C function that is supposed to accept variadic arguments. The Redis Module C SDK has a function called RedisModule_Call which accepts a few specific arguments then n arguments that represent a Redis command. From the Redis Module SDK documentation (in C): RedisModuleCallReply *reply; reply = RedisModule_Call(ctx,"INCR","sc",argv[1],"10"); RedisModule_Call 's first three arguments are specific, but the rest represent Redis commands that could easily have hundreds of arguments. In

How can I create an Array class in C++11 which can be used like Array < int, 2, 3, 4> a, b; Array < char, 3, 4> d; Array < short, 2> e; and access it in a way like a[2][1][2] = 15; d[1][2] ='a'; I also need to overload operator as T &operator[size_t i_1][size_t i_2]...[size_t i_D]; which does not exist. How can I do this? The simplest way to do this is by nesting std::array : #include<array> template<class T, size_t size, size_t... sizes> struct ArrayImpl { using type = std::array<typename ArrayImpl<T, sizes...>::type, size>; }; template<class T, size_t size> struct ArrayImpl<T, size> { using

I try to create bulk insert. I use gorm github.com/jinzhu/gorm import ( "fmt" dB "github.com/edwinlab/api/repositories" ) func Update() error { tx := dB.GetWriteDB().Begin() sqlStr := "INSERT INTO city(code, name) VALUES (?, ?),(?, ?)" vals := []interface{}{} vals = append(vals, "XX1", "Jakarta") vals = append(vals, "XX2", "Bandung") tx.Exec(sqlStr, vals) tx.Commit() return nil } But I got an error: Error 1136: Column count doesn't match value count at row 1 becuse i return wrong query INSERT INTO city(code, name) VALUES ('XX1','Jakarta','XX2','Bandung', %!v(MISSING)),(%!v(MISSING), %!v