// N4606 Committee Draft, Standard for Programming Language C++
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/n4606.pdf
#define msg "(170)14.3.2 Template non-type arguments [temp.arg.nontype]p355.cpp"
// Edited by Dr. Ogawa Kiyoshi. Compile procedure and results record.

#include <iostream>

template<const int* pci> struct X { /* ... */
};
int ai[10];
X<ai> xi; // array to pointer and qualification conversions
struct Y { /* ... */
};
template<const Y& b> struct Z { /* ... */
};
Y y;
Z<y> z; // no conversion, but note extra cv-qualification
template<int (&pa)[5]> struct W { /* ... */
};
int b[5];
W<b> w; // no conversion
void f(char);
void f(int);
template<void (*pf)(int)> struct A { /* ... */
};
A<&f> a; // selects f(int)
template<auto n> struct B { /* ... */
};
B<5> b1; // OK: template parameter type is int
B<'a'> b2; // OK: template parameter type is char
B<2.5> b3; // error: template parameter type cannot be double

template<class T, const char* p> class X {
  /* ... */
};
X<int, "Studebaker"> x1; // error: string literal as template-argument
const char p[] = "Vivisectionist";
X<int,p> x2; // OK

template<int* p> class X { };
int a2[10];
struct S {
  int m;
  static int s;
} s;
X<&a[2]> x3; // error: address of array element
X<&s.m> x4; // error: address of non-static member
X<&s.s> x5; // OK: address of static member
X<&S::s> x6; // OK: address of static member

template<const int& CRI> struct B2 { /* ... */
};
B2<1> b2a; // error: temporary would be required for template argument
int c = 1;
B2<c> b1a; // OK

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

$ ./cppgl17.sh p355
$ clang++ p355.cpp
p355.cpp:25:3: error: a non-type template parameter cannot have type 'double'
B<2.5> b3; // error: template parameter type cannot be double
  ^
p355.cpp:22:15: note: template parameter is declared here
template<auto n> struct B { /* ... */ };
              ^
p355.cpp:27:1: error: too many template parameters in template redeclaration
template<class T, const char* p> class X {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
p355.cpp:8:1: note: previous template declaration is here
template<const int* pci> struct X { /* ... */ };
^~~~~~~~~~~~~~~~~~~~~~~~
p355.cpp:30:3: error: template argument for non-type template parameter must be an expression
X<int, "Studebaker"> x1; // error: string literal as template-argument
  ^~~
p355.cpp:8:21: note: template parameter is declared here
template<const int* pci> struct X { /* ... */ };
                    ^
p355.cpp:32:3: error: template argument for non-type template parameter must be an expression
X<int,p> x2; // OK
  ^~~
p355.cpp:8:21: note: template parameter is declared here
template<const int* pci> struct X { /* ... */ };
                    ^
p355.cpp:34:15: error: template non-type parameter has a different type 'int *' in template redeclaration
template<int* p> class X { };
              ^
p355.cpp:8:21: note: previous non-type template parameter with type 'const int *' is here
template<const int* pci> struct X { /* ... */ };
                    ^
p355.cpp:37:5: error: type 'A<&f>' does not provide a subscript operator
X<&a[2]> x3; // error: address of array element
   ~^~
p355.cpp:38:3: error: non-type template argument refers to subobject '&s.m'
X<&s.m> x4; // error: address of non-static member
  ^
p355.cpp:43:4: error: conversion from 'int' to 'const int &' in converted constant expression would bind reference to a temporary
B2<1> b2a; // error: temporary would be required for template argument
   ^
p355.cpp:48:3: error: no matching function for call to 'f'
  f();
  ^
p355.cpp:19:6: note: candidate function not viable: requires 1 argument, but 0 were provided
void f(int);
     ^
p355.cpp:18:6: note: candidate function not viable: requires 1 argument, but 0 were provided
void f(char);
     ^
9 errors generated.

$ g++-7 p355.cpp
p355.cpp:25:6: error: 'double' is not a valid type for a template non-type parameter
 B<2.5> b3; // error: template parameter type cannot be double
      ^
p355.cpp:27:40: error: redeclared with 2 template parameters
 template<class T, const char* p> class X {
                                        ^
p355.cpp:8:33: note: previous declaration 'template<const int* pci> struct X' used 1 template parameter
 template<const int* pci> struct X { /* ... */ };
                                 ^
p355.cpp:30:20: error: wrong number of template arguments (2, should be 1)
 X<int, "Studebaker"> x1; // error: string literal as template-argument
                    ^
p355.cpp:8:33: note: provided for 'template<const int* pci> struct X'
 template<const int* pci> struct X { /* ... */ };
                                 ^
p355.cpp:32:8: error: wrong number of template arguments (2, should be 1)
 X<int,p> x2; // OK
        ^
p355.cpp:8:33: note: provided for 'template<const int* pci> struct X'
 template<const int* pci> struct X { /* ... */ };
                                 ^
p355.cpp:8:21: error: template parameter 'const int* pci'
 template<const int* pci> struct X { /* ... */ };
                     ^~~
p355.cpp:34:24: error: redeclared here as 'int* p'
 template<int* p> class X { };
                        ^
p355.cpp:37:5: error: no match for 'operator[]' (operand types are 'A<f>' and 'int')
 X<&a[2]> x3; // error: address of array element
     ^
p355.cpp:37:8: error: template argument 1 is invalid
 X<&a[2]> x3; // error: address of array element
        ^
p355.cpp:38:7: error: '& s.S::m' is not a valid template argument of type 'const int*' because 's.S::m' is not a variable
 X<&s.m> x4; // error: address of non-static member
       ^
p355.cpp:43:5: error: '1' is not a valid template argument for type 'const int&' because it is not an lvalue
 B2<1> b2a; // error: temporary would be required for template argument
     ^
p355.cpp: In function 'int main()':
p355.cpp:48:5: error: no matching function for call to 'f()'
   f();
     ^
p355.cpp:18:6: note: candidate: void f(char)
 void f(char);
      ^
p355.cpp:18:6: note:   candidate expects 1 argument, 0 provided
p355.cpp:19:6: note: candidate: void f(int)
 void f(int);
      ^
p355.cpp:19:6: note:   candidate expects 1 argument, 0 provided

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