llvm-project/clang/test/SemaTemplate/instantiate-member-template.cpp

// RUN: %clang_cc1 -fsyntax-only -verify %s

template<typename T>
struct X0 {
  template<typename U> T f0(U);
  template<typename U> U& f1(T*, U); // expected-error{{pointer to a reference}} \
                                     // expected-note{{candidate}}
};

X0<int> x0i;
X0<void> x0v;
X0<int&> x0ir; // expected-note{{instantiation}}

void test_X0(int *ip, double *dp) {
  X0<int> xi;
  int i1 = xi.f0(ip);
  double *&dpr = xi.f1(ip, dp);
  xi.f1(dp, dp); // expected-error{{no matching}}

  X0<void> xv;
  double *&dpr2 = xv.f1(ip, dp);
}

template<typename T>
struct X1 {
  template<typename U>
  struct Inner0 {
    U x; 
    T y; // expected-error{{void}}
  };

  template<typename U>
  struct Inner1 {
    U x; // expected-error{{void}}
    T y;
  };
  
  template<typename U>
  struct Inner2 {
    struct SuperInner {
      U z; // expected-error{{void}}
    };
  };
  
  template<typename U>
  struct Inner3 {
    void f0(T t, U u) {
      (void)(t + u); // expected-error{{invalid operands}}
    }
    
    template<typename V>
    V f1(T t, U u, V) {
      return t + u; // expected-error{{cannot initialize return object}}
    }
  };
  
  template<typename U>
  struct Inner4;
};

template<typename T>
template<typename U>
struct X1<T>::Inner4 {
  template<typename V>
  V f2(T t, U u, V);
  
  static U value;
};

template<typename T>
template<typename U>
U X1<T>::Inner4<U>::value; // expected-error{{reference variable}}

template<typename T>
template<typename U>
template<typename V>
V X1<T>::Inner4<U>::f2(T t, U u, V) {
  return t + u; // expected-error{{cannot initialize return object}}
}

void test_X1(int *ip, int i, double *dp) {
  X1<void>::Inner0<int> *xvip; // okay
  X1<void>::Inner0<int> xvi; // expected-note{{instantiation}}
  
  X1<int>::Inner1<void> *xivp; // okay
  X1<int>::Inner1<void> xiv; // expected-note{{instantiation}}
  
  X1<int>::Inner2<void>::SuperInner *xisivp; // okay
  X1<int>::Inner2<void>::SuperInner xisiv; // expected-note{{instantiation}}
  
  X1<int*>::Inner3<int> id3;
  id3.f0(ip, i);
  id3.f0(dp, i); // expected-error{{incompatible type}}
  id3.f1(ip, i, ip);
  id3.f1(ip, i, dp); // expected-note{{instantiation}}
  
  X1<int*>::Inner3<double*> id3b;
  id3b.f0(ip, dp); // expected-note{{instantiation}}
  
  X1<int*>::Inner4<int> id4;
  id4.f2(ip, i, dp); // expected-note{{instantiation}}
  
  X1<int*>::Inner4<int>::value = 17;
  i = X1<int*>::Inner4<int&>::value; // expected-note{{instantiation}}
}


template<typename T>
struct X2 {
  template<T *Ptr> // expected-error{{pointer to a reference}}
  struct Inner;
  
  template<T Value> // expected-error{{cannot have type 'float'}}
  struct Inner2;
};

X2<int&> x2a; // expected-note{{instantiation}}
X2<float> x2b; // expected-note{{instantiation}}

namespace N0 {
  template<typename T>
  struct X0 { };
  
  struct X1 {
    template<typename T> void f(X0<T>& vals) { g(vals); }
    template<typename T> void g(X0<T>& vals) { }
  };
  
  void test(X1 x1, X0<int> x0i, X0<long> x0l) {
    x1.f(x0i);
    x1.f(x0l);
  }  
}