// C++N4741 Committee Draft, Standard for Programming Language C++
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/n741.pdf
const char* msg= "C++N4741(212)17.7.1 Locally declared names [temp.local]p348.cpp";
// Edited by Dr. Ogawa Kiyoshi. Compile procedure and results record.

#include <iostream>
#include <cstdlib>

using namespace std;

namespace N {
  template<template<class> class T> class A { };
  template<class T> class Y;
  template<> class Y<int> {
    Y* p; // meaning Y<int>
    Y<char>* q; // meaning Y<char>
    A<Y>* a; // meaning A<::Y>
    class B {
      template<class> friend class Y; // meaning ::Y
    };
  };
}

namespace M {
  template <class T> struct Base {
    Base* p;
  };
  template <class T> struct Derived: public Base<T> {
    typename Derived::Base* p; // meaning Derived::Base<T>
  };
  template<class T, template<class> class U = T::template Base> struct Third { };
  Third<Derived<int> > t; // OK: default argument uses injected-class-name as a template
}

namespace P {
  template <class T> struct Base { };
  template <class T> struct Derived: Base<int>, Base<char> {
    typename Derived::Base b; // error: ambiguous
    typename Derived::Base<double> d; // OK
  };
}

namespace Q {
  template<class T> class X {
    X* p; // meaning X<T>
    X<T>* p2;
    X<int>* p3;
    ::X* p4; // error: missing template argument list
// ::X does not refer to the injected-class-name
  };
}

namespace R {
  template<class T, int i> class Y {
    int T; // error: template-parameter redeclared
    void f() {
      char T; // error: template-parameter redeclared
    }
  };
  template<class X> class X; // error: template-parameter redeclared
}

namespace S {
  template<class T> struct A {
    struct B { /* ... */
    };
    typedef void C;
    void f();
    template<class U> void g(U);
  };
  template<class B> void A<B>::f() {
    B b; // A’s B, not the template parameter
  }
  template<class B> template<class C> void A<B>::g(C) {
    B b; // A’s B, not the template parameter
    C c; // the template parameter C, not A’s C
  }
}

namespace N {
  class C { };
  template<class T> class B {
    void f(T);
  };
}
template<class C> void N::B<C>::f(C) {
  C b; // C is the template parameter, not N::C
}

namespace U {
  struct A {
    struct B { /* ... */
    };
    int a;
    int Y;
  };
  template<class B, class a> struct X : A {
    B b; // A’s B
    a b; // error: A’s a isn’t a type name
  };
}

int main() {

  cout << msg << endl;
  return EXIT_SUCCESS;
}

$ ../c1.sh p348
$ clang++ p348.cpp  -std=c++2a -Wall
p348.cpp:38:19: error: member 'Base' found in multiple base classes of different types
typename Derived::Base b; // error: ambiguous
                  ^
p348.cpp:36:27: note: member found by ambiguous name lookup
template <class T> struct Base { };
                          ^
p348.cpp:36:27: note: member found by ambiguous name lookup
p348.cpp:48:1: error: no type named 'X' in the global namespace; did you mean simply 'X'?
::X* p4; // error: missing template argument list
^~~
X
p348.cpp:44:25: note: 'X' declared here
template<class T> class X {
                        ^
p348.cpp:55:5: error: declaration of 'T' shadows template parameter
int T; // error: template-parameter redeclared
    ^
p348.cpp:54:16: note: template parameter is declared here
template<class T, int i> class Y {
               ^
p348.cpp:57:6: warning: unused variable 'T' [-Wunused-variable]
char T; // error: template-parameter redeclared
     ^
p348.cpp:60:25: error: declaration of 'X' shadows template parameter
template<class X> class X; // error: template-parameter redeclared
                        ^
p348.cpp:60:16: note: template parameter is declared here
template<class X> class X; // error: template-parameter redeclared
               ^
p348.cpp:73:48: error: out-of-line definition of 'g' does not match any declaration in
      'A<T>'
template<class B> template<class C> void A<B>::g(C) {
                                               ^
p348.cpp:75:3: error: variable has incomplete type 'S::A::C' (aka 'void')
C c; // the template parameter C, not A’s C
  ^
p348.cpp:97:1: error: unknown type name 'a'
a b; // error: A’s a isn’t a type name
^
p348.cpp:97:3: error: duplicate member 'b'
a b; // error: A’s a isn’t a type name
  ^
p348.cpp:96:3: note: previous declaration is here
B b; // A’s B
  ^
p348.cpp:15:4: warning: private field 'p' is not used [-Wunused-private-field]
Y* p; // meaning Y<int>
   ^
p348.cpp:16:10: warning: private field 'q' is not used [-Wunused-private-field]
Y<char>* q; // meaning Y<char>
         ^
p348.cpp:17:7: warning: private field 'a' is not used [-Wunused-private-field]
A<Y>* a; // meaning A<::Y>
      ^
4 warnings and 8 errors generated.

// C++N4741 Committee Draft, Standard for Programming Language C++
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/n741.pdf
const char* msg= "C++N4741(212)17.7.1 Locally declared names [temp.local]p348.cpp";
// Edited by Dr. Ogawa Kiyoshi. Compile procedure and results record.

#include <iostream>
#include <cstdlib>

using namespace std;

namespace N {
  template<template<class> class T> class A { };
  template<class T> class Y;
  template<> class Y<int> {
    Y* p; // meaning Y<int>
    Y<char>* q; // meaning Y<char>
    A<Y>* a; // meaning A<::Y>
    class B {
      template<class> friend class Y; // meaning ::Y
    };
  };
}

namespace M {
  template <class T> struct Base {
    Base* p;
  };
  template <class T> struct Derived: public Base<T> {
    typename Derived::Base* p; // meaning Derived::Base<T>
  };
  template<class T, template<class> class U = T::template Base> struct Third { };
  Third<Derived<int> > t; // OK: default argument uses injected-class-name as a template
}

namespace P {
  template <class T> struct Base { };
  template <class T> struct Derived: Base<int>, Base<char> {
///typename Derived::Base b; // error: ambiguous
    typename Derived::Base<double> d; // OK
  };
}

namespace Q {
  template<class T> class X {
    X* p; // meaning X<T>
    X<T>* p2;
    X<int>* p3;
///Q::X* p4; // error: missing template argument list ///add Q for namespace
// ::X does not refer to the injected-class-name
  };
}

namespace R {
  template<class T, int i> class Y {
///int T; // error: template-parameter redeclared
    void f() {
///char T; // error: template-parameter redeclared
    }
  };
///template<class X> class X; // error: template-parameter redeclared
}

namespace S {
  template<class T> struct A {
    struct B { /* ... */
    };
    typedef void C;
    void f();
    template<class U> void g(U);
  };
  template<class B> void A<B>::f() {
    B b; // A’s B, not the template parameter
  }
///template<class B> template<class C> void A<B>::g(C) {///error: out-of-line definition of 'g' does not match any declaration in 'A<T>'
///B b; // A’s B, not the template parameter///  error: unknown type name 'B'
///C c; // the template parameter C, not A’s C///error: variable has incomplete type 'S::A::C' (aka 'void')
///}
}

namespace N {
  class C { };
  template<class T> class B {
    void f(T);
  };
}
template<class C> void N::B<C>::f(C) {
  C b; // C is the template parameter, not N::C
}

namespace U {
  struct A {
    struct B { /* ... */
    };
    int a;
    int Y;
  };
  template<class B, class a> struct X : A {
    B b; // A’s B
///a b; // error: A’s a isn’t a type name
  };
}

int main() {

  cout << msg << endl;
  return EXIT_SUCCESS;
}

$ ../cpla.sh p348a
$ clang++ p348a.cpp -std=c++03 -Wall
p348a.cpp:15:4: warning: private field 'p' is not used [-Wunused-private-field]
Y* p; // meaning Y<int>
   ^
p348a.cpp:16:10: warning: private field 'q' is not used [-Wunused-private-field]
Y<char>* q; // meaning Y<char>
         ^
p348a.cpp:17:7: warning: private field 'a' is not used [-Wunused-private-field]
A<Y>* a; // meaning A<::Y>
      ^
3 warnings generated.
C++N4741(212)17.7.1 Locally declared names [temp.local]p348.cpp
$ clang++ p348a.cpp -std=c++2a -Wall
p348a.cpp:15:4: warning: private field 'p' is not used [-Wunused-private-field]
Y* p; // meaning Y<int>
   ^
p348a.cpp:16:10: warning: private field 'q' is not used [-Wunused-private-field]
Y<char>* q; // meaning Y<char>
         ^
p348a.cpp:17:7: warning: private field 'a' is not used [-Wunused-private-field]
A<Y>* a; // meaning A<::Y>
      ^
3 warnings generated.
C++N4741(212)17.7.1 Locally declared names [temp.local]p348.cpp

$ g++-8 p348a.cpp -std=c++03  -Wall
C++N4741(212)17.7.1 Locally declared names [temp.local]p348.cpp

$ g++-8 p348a.cpp -std=c++2a  -Wall
C++N4741(212)17.7.1 Locally declared names [temp.local]p348.cpp