// N4606 Committee Draft, Standard for Programming Language C++
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/n4606.pdf 
#define msg "p209.cpp(97)8.3.5 Functions [dcl.ptr]"

#include <iostream>

void h(){
int a=1, b=2;
//int printf(const char*, ...);
printf("hello world");
printf("a=%d b=%d", a, b);
}

typedef int FIC(int) const;
FIC f; // ill-formed: does not declare a member function
struct S1 {
  FIC f; // OK
};
FIC S1::*pm = &S1::f; // OK

typedef void F();
struct S {
  const F f; // OK: equivalent to: void f();
};

int fseek(FILE*, long, int);

typedef void F();
F fv; // OK: equivalent to void fv();
F fv { } // ill-formed
void fv() { } // OK: definition of fv

int i,
*pi,
f(),
*fpi(int),
(*pif)(const char*, const char*),
(*fpif(int))(int);

typedef int IFUNC(int);
IFUNC* fpif(int);
auto fpif(int)->int(*)(int);

template <class T, class U> auto add(T t, U u) -> decltype(t + u);

template <class T, class U> decltype((*(T*)0) + (*(U*)0)) add(T t, U u);

template<typename... T> void f(T (* ...t)(int, int));
int add(int, int);
float subtract(int, int);

void g() {
  f(add, subtract);
}

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

$ ./cppgl17.sh p209
$ clang++ p209.cpp
p209.cpp:15:1: error: non-member function of type 'FIC' (aka 'int (int) const') cannot have 'const' qualifier
FIC f; // ill-formed: does not declare a member function
^
p209.cpp:23:3: warning: 'const' qualifier on function type 'F' (aka 'void ()') has no effect [-Wignored-qualifiers]
  const F f; // OK: equivalent to: void f();
  ^~~~~~
p209.cpp:30:3: error: illegal initializer (only variables can be initialized)
F fv { } // ill-formed
  ^
p209.cpp:30:9: error: expected ';' after top level declarator
F fv { } // ill-formed
        ^
        ;
p209.cpp:52:3: error: no matching function for call to 'f'
  f(add, subtract);
  ^
p209.cpp:48:30: note: candidate template ignored: substitution failure : deduced incomplete pack <(no value), float> for template parameter
      'T'
template<typename... T> void f(T (* ...t)(int, int));
                     ~       ^
p209.cpp:15:5: note: candidate function not viable: requires 1 argument, but 2 were provided
FIC f; // ill-formed: does not declare a member function
    ^
p209.cpp:35:1: note: candidate function not viable: requires 0 arguments, but 2 were provided
f(),
^
1 warning and 4 errors generated.

$ g++-7 p209.cpp
p209.cpp:15:5: error: non-member function 'int f(int)' cannot have cv-qualifier
 FIC f; // ill-formed: does not declare a member function
     ^
p209.cpp:30:8: error: function 'void fv()' is initialized like a variable
 F fv { } // ill-formed
        ^
p209.cpp:31:1: error: expected ',' or ';' before 'void'
 void fv() { } // OK: definition of fv
 ^~~~
p209.cpp: In function 'void g()':
p209.cpp:52:18: error: no matching function for call to 'f(<unresolved overloaded function type>, float (&)(int, int))'
   f(add, subtract);
                  ^
p209.cpp:15:5: note: candidate: int f(int)
 FIC f; // ill-formed: does not declare a member function
     ^
p209.cpp:15:5: note:   candidate expects 1 argument, 2 provided
p209.cpp:35:1: note: candidate: int f()
 f(),
 ^
p209.cpp:35:1: note:   candidate expects 0 arguments, 2 provided
p209.cpp:48:30: note: candidate: void f(T (*)(int, int) ...) [with T = {}]
 template<typename... T> void f(T (* ...t)(int, int));
                              ^
p209.cpp:48:30: note:   candidate expects 0 arguments, 2 provided