// N4606 Committee Draft, Standard for Programming Language C++
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/n4606.pdf
#define msg "(180)14.5.3 Variadic templates [temp.variadic] p362.cpp"
// Edited by Dr. Ogawa Kiyoshi. Compile procedure and results record.

#include <iostream>

template<class ... Types> struct Tuple { };
Tuple<> t0; // Types contains no arguments
Tuple<int> t1; // Types contains one argument: int
Tuple<int, float> t2; // Types contains two arguments: int and float
Tuple<0> error; // error: 0 is not a type

template<class ... Types> void f(Types ... args);
f(); // OK: args contains no arguments
f(1); // OK: args contains one argument: int
f(2, 1.0); // OK: args contains two arguments: int and double

template<class ... Types> void f(Types ... rest);
template<class ... Types> void g(Types ... rest) {
f(&rest ...); // “&rest ...” is a pack expansion; “&rest” is its pattern
}

template<typename...> struct Tuple {};
template<typename T1, typename T2> struct Pair {};
template<class ... Args1> struct zip {
template<class ... Args2> struct with {
typedef Tuple<Pair<Args1, Args2> ... > type;
};
};

typedef zip<short, int>::with<unsigned short, unsigned>::type T1;
// T1 is Tuple<Pair<short, unsigned short>, Pair<int, unsigned>>
typedef zip<short>::with<unsigned short, unsigned>::type T2;
// error: different number of arguments specified for Args1 and Args2
template<class ... Args>
void g(Args ... args) { // OK: Args is expanded by the function parameter pack args
f(const_cast<const Args*>(&args)...); // OK: “Args” and “args” are expanded
f(5 ...); // error: pattern does not contain any parameter packs
f(args); // error: parameter pack “args” is not expanded
f(h(args ...) + args ...); // OK: first “args” expanded within h, second
// “args” expanded within f
}

template<class... T> struct X : T... { };
template<class... T> void f(T... values) {
X<T...> x(values...);
}
template void f<>(); // OK: X<> has no base classes
// x is a variable of type X<> that is value-initialized

template<typename ...Args>
bool all(Args ...args) { return (... && args); }
bool b = all(true, true, true, false);

int main() {
  std::cout<< msg << std::endl;
  return EXIT_SUCCESS;
}

$ ./cppgl17.sh p362
$ clang++ p362.cpp
p362.cpp:12:7: error: template argument for template type parameter must be a type
Tuple<0> error; // error: 0 is not a type
      ^
p362.cpp:8:20: note: template parameter is declared here
template<class ... Types> struct Tuple { };
                   ^
p362.cpp:15:1: error: C++ requires a type specifier for all declarations
f(); // OK: args contains no arguments
^
p362.cpp:16:1: error: C++ requires a type specifier for all declarations
f(1); // OK: args contains one argument: int
^
p362.cpp:17:1: error: C++ requires a type specifier for all declarations
f(2, 1.0); // OK: args contains two arguments: int and double
^
p362.cpp:24:30: error: redefinition of 'Tuple'
template<typename...> struct Tuple {};
                             ^
p362.cpp:8:34: note: previous definition is here
template<class ... Types> struct Tuple { };
                                 ^
p362.cpp:28:34: error: pack expansion contains parameter packs 'Args1' and 'Args2' that have different lengths (1 vs. 2)
typedef Tuple<Pair<Args1, Args2> ... > type;
                   ~~~~~  ~~~~~  ^
p362.cpp:34:21: note: in instantiation of template class 'zip<short>::with<unsigned short, unsigned int>' requested here
typedef zip<short>::with<unsigned short, unsigned>::type T2;
                    ^
p362.cpp:39:5: error: pack expansion does not contain any unexpanded parameter packs
f(5 ...); // error: pattern does not contain any parameter packs
  ~ ^
p362.cpp:40:1: error: expression contains unexpanded parameter pack 'args'
f(args); // error: parameter pack “args” is not expanded
^ ~~~~
8 errors generated.

$ g++-7 p362.cpp
p362.cpp:12:8: error: type/value mismatch at argument 1 in template parameter list for 'template<class ... Types> struct Tuple'
 Tuple<0> error; // error: 0 is not a type
        ^
p362.cpp:12:8: note:   expected a type, got '0'
p362.cpp:15:4: error: expected constructor, destructor, or type conversion before ';' token
 f(); // OK: args contains no arguments
    ^
p362.cpp:16:2: error: expected constructor, destructor, or type conversion before '(' token
 f(1); // OK: args contains one argument: int
  ^
p362.cpp:17:2: error: expected constructor, destructor, or type conversion before '(' token
 f(2, 1.0); // OK: args contains two arguments: int and double
  ^
p362.cpp:24:30: error: redefinition of 'struct Tuple<Types>'
 template<typename...> struct Tuple {};
                              ^~~~~
p362.cpp:8:34: note: previous definition of 'struct Tuple<Types>'
 template<class ... Types> struct Tuple { };
                                  ^~~~~
p362.cpp: In instantiation of 'struct zip<short int>::with<short unsigned int, unsigned int>':
p362.cpp:34:51:   required from here
p362.cpp:28:40: error: mismatched argument pack lengths while expanding 'Pair<Args1, Args2>'
 typedef Tuple<Pair<Args1, Args2> ... > type;
                                        ^~~~
p362.cpp: In function 'void g(Args ...)':
p362.cpp:39:5: error: expansion pattern '5' contains no argument packs
 f(5 ...); // error: pattern does not contain any parameter packs
     ^~~
p362.cpp:40:2: error: parameter packs not expanded with '...':
 f(args); // error: parameter pack “args” is not expanded
 ~^~~~~~
p362.cpp:40:2: note:         'args'

#!/bin/bash
astyle -s2 -c < $1.cpp > $1s2.cpp
cat $1s2.cpp