// RUN: %clang_cc1 -std=c++98 -triple x86_64-unknown-unknown %s -verify -fexceptions -fcxx-exceptions -pedantic-errors // RUN: %clang_cc1 -std=c++11 -triple x86_64-unknown-unknown %s -verify -fexceptions -fcxx-exceptions -pedantic-errors // RUN: %clang_cc1 -std=c++14 -triple x86_64-unknown-unknown %s -verify -fexceptions -fcxx-exceptions -pedantic-errors // RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-unknown %s -verify -fexceptions -fcxx-exceptions -pedantic-errors namespace dr100 { // dr100: yes template struct A {}; // expected-note 0-1{{declared here}} template struct B {}; // expected-note 0-1{{declared here}} A<"foo"> a; // expected-error {{does not refer to any declaration}} B<"bar"> b; // expected-error {{does not refer to any declaration}} } namespace dr101 { // dr101: 3.5 extern "C" void dr101_f(); typedef unsigned size_t; namespace X { extern "C" void dr101_f(); typedef unsigned size_t; } using X::dr101_f; using X::size_t; extern "C" void dr101_f(); typedef unsigned size_t; } namespace dr102 { // dr102: yes namespace A { template T f(T a, T b) { return a + b; } // expected-error {{neither visible in the template definition nor found by argument-dependent lookup}} } namespace B { struct S {}; } B::S operator+(B::S, B::S); // expected-note {{should be declared prior to the call site or in namespace 'dr102::B'}} template B::S A::f(B::S, B::S); // expected-note {{in instantiation of}} } // dr103: na // dr104: na lib // dr105: na namespace dr106 { // dr106: sup 540 typedef int &r1; typedef r1 &r1; typedef const r1 r1; // expected-warning {{has no effect}} typedef const r1 &r1; // expected-warning {{has no effect}} typedef const int &r2; typedef r2 &r2; typedef const r2 r2; // expected-warning {{has no effect}} typedef const r2 &r2; // expected-warning {{has no effect}} } namespace dr107 { // dr107: yes struct S {}; extern "C" S operator+(S, S) { return S(); } } namespace dr108 { // dr108: yes template struct A { struct B { typedef int X; }; B::X x; // expected-error {{missing 'typename'}} struct C : B { X x; }; // expected-error {{unknown type name}} }; template<> struct A::B { int X; }; } namespace dr109 { // dr109: yes struct A { template void f(T); }; template struct B : T { using T::template f; // expected-error {{'template' keyword not permitted here}} using T::template f; // expected-error {{'template' keyword not permitted here}} expected-error {{using declaration cannot refer to a template specialization}} // FIXME: We shouldn't suggest using the 'template' keyword in a location where it's not valid. using T::f; // expected-error {{use 'template' keyword}} expected-error {{using declaration cannot refer to a template specialization}} void g() { this->f(123); } // expected-error {{use 'template' keyword}} }; } namespace dr111 { // dr111: dup 535 struct A { A(); A(volatile A&, int = 0); A(A&, const char * = "foo"); }; struct B : A { B(); }; // expected-note +{{would lose const qualifier}} expected-note {{requires 0 arguments}} const B b1; B b2(b1); // expected-error {{no matching constructor}} } namespace dr112 { // dr112: yes struct T { int n; }; typedef T Arr[1]; const T a1[1] = {}; volatile T a2[1] = {}; const Arr a3 = {}; volatile Arr a4 = {}; template struct X {}; X x1; X x2; X x3; X x4; #if __cplusplus < 201103L // expected-error@-5 {{internal linkage}} expected-note@-10 {{here}} // expected-error@-4 {{internal linkage}} expected-note@-9 {{here}} #else // FIXME: Test this somehow. #endif } namespace dr113 { // dr113: yes extern void (*p)(); void f() { no_such_function(); // expected-error {{undeclared}} p(); } void g(); void (*p)() = &g; } namespace dr114 { // dr114: yes struct A { virtual void f(int) = 0; // expected-note {{unimplemented}} }; struct B : A { template void f(T); void g() { f(0); } } b; // expected-error {{abstract}} } namespace dr115 { // dr115: yes template int f(T); // expected-note +{{}} template int g(T); // expected-note +{{}} template int g(T, int); // expected-note +{{}} int k1 = f(&f); // expected-error {{no match}} int k2 = f(&f); int k3 = f(&g); // expected-error {{no match}} void h() { (void)&f; // expected-error {{address of overloaded function 'f' cannot be cast to type 'void'}} (void)&f; (void)&g; // expected-error {{address of overloaded function 'g' cannot be cast to type 'void'}} &f; // expected-error {{reference to overloaded function could not be resolved}} &f; // expected-warning {{unused}} &g; // expected-error {{reference to overloaded function could not be resolved}} } struct S { template static int f(T); template static int g(T); template static int g(T, int); } s; int k4 = f(&s.f); // expected-error {{non-constant pointer to member}} int k5 = f(&s.f); int k6 = f(&s.g); // expected-error {{non-constant pointer to member}} void i() { (void)&s.f; // expected-error {{non-constant pointer to member}} (void)&s.f; (void)&s.g; // expected-error {{non-constant pointer to member}} &s.f; // expected-error {{non-constant pointer to member}} &s.f; // expected-warning {{unused}} &s.g; // expected-error {{non-constant pointer to member}} } struct T { template int f(T); template int g(T); template int g(T, int); } t; int k7 = f(&s.f); // expected-error {{non-constant pointer to member}} int k8 = f(&s.f); int k9 = f(&s.g); // expected-error {{non-constant pointer to member}} void j() { (void)&s.f; // expected-error {{non-constant pointer to member}} (void)&s.f; (void)&s.g; // expected-error {{non-constant pointer to member}} &s.f; // expected-error {{non-constant pointer to member}} &s.f; // expected-warning {{unused}} &s.g; // expected-error {{non-constant pointer to member}} } #if __cplusplus >= 201103L // Special case kicks in only if a template argument list is specified. template void with_default(); // expected-note +{{}} int k10 = f(&with_default); // expected-error {{no matching function}} int k11 = f(&with_default<>); void k() { (void)&with_default; // expected-error {{overloaded function}} (void)&with_default<>; &with_default; // expected-error {{overloaded function}} &with_default<>; // expected-warning {{unused}} } #endif } namespace dr116 { // dr116: yes template struct A {}; template void f(A) {} // expected-note {{previous}} template void f(A) {} // expected-error {{redefinition}} template void f(A) {} // expected-note {{previous}} template void f(A) {} // expected-error {{redefinition}} } // dr117: na // dr118 is in its own file. // dr119: na // dr120: na namespace dr121 { // dr121: yes struct X { template struct Y {}; }; template struct Z { X::Y x; T::Y y; // expected-error +{{}} }; Z z; } namespace dr122 { // dr122: yes template void f(); void g() { f(); } } // dr123: na // dr124: dup 201 // dr125: yes struct dr125_A { struct dr125_B {}; }; // expected-note {{here}} dr125_A::dr125_B dr125_C(); namespace dr125_B { dr125_A dr125_C(); } namespace dr125 { struct X { friend dr125_A::dr125_B (::dr125_C)(); // ok friend dr125_A (::dr125_B::dr125_C)(); // ok friend dr125_A::dr125_B::dr125_C(); // expected-error {{did you mean the constructor name 'dr125_B'?}} // expected-error@-1 {{missing exception specification}} }; } namespace dr126 { // dr126: partial // FIXME: We do not yet generate correct code for this change: // eg: // catch (void*&) should catch void* but not int* // catch (void*) and catch (void*const&) should catch both // Likewise: // catch (Base *&) should catch Base* but not Derived* // catch (Base *) should catch both // In each case, we emit the same code for both catches. // // The ABI does not let us represent the language rule in the unwind tables. // So, when catching by non-const (or volatile) reference to pointer, we // should compare the exception type to the caught type and only accept an // exact match. #if __cplusplus <= 201402L struct C {}; struct D : C {}; struct E : private C { friend class A; friend class B; }; struct F : protected C {}; struct G : C {}; struct H : D, G {}; struct A { virtual void cp() throw(C*); virtual void dp() throw(C*); virtual void ep() throw(C*); // expected-note {{overridden}} virtual void fp() throw(C*); // expected-note {{overridden}} virtual void gp() throw(C*); virtual void hp() throw(C*); // expected-note {{overridden}} virtual void cr() throw(C&); virtual void dr() throw(C&); virtual void er() throw(C&); // expected-note {{overridden}} virtual void fr() throw(C&); // expected-note {{overridden}} virtual void gr() throw(C&); virtual void hr() throw(C&); // expected-note {{overridden}} virtual void pv() throw(void*); #if __cplusplus >= 201103L virtual void np() throw(C*); virtual void npm() throw(int C::*); virtual void nr() throw(C*&); // expected-note {{overridden}} virtual void ncr() throw(C*const&); #endif virtual void ref1() throw(C *const&); virtual void ref2() throw(C *); virtual void v() throw(int); virtual void w() throw(const int); virtual void x() throw(int*); // expected-note {{overridden}} virtual void y() throw(const int*); virtual void z() throw(int); // expected-note {{overridden}} }; struct B : A { virtual void cp() throw(C*); virtual void dp() throw(D*); virtual void ep() throw(E*); // expected-error {{more lax}} virtual void fp() throw(F*); // expected-error {{more lax}} virtual void gp() throw(G*); virtual void hp() throw(H*); // expected-error {{more lax}} virtual void cr() throw(C&); virtual void dr() throw(D&); virtual void er() throw(E&); // expected-error {{more lax}} virtual void fr() throw(F&); // expected-error {{more lax}} virtual void gr() throw(G&); virtual void hr() throw(H&); // expected-error {{more lax}} virtual void pv() throw(C*); #if __cplusplus >= 201103L using nullptr_t = decltype(nullptr); virtual void np() throw(nullptr_t); virtual void npm() throw(nullptr_t&); virtual void nr() throw(nullptr_t); // expected-error {{more lax}} virtual void ncr() throw(nullptr_t); #endif virtual void ref1() throw(D *const &); virtual void ref2() throw(D *); virtual void v() throw(const int); virtual void w() throw(int); virtual void x() throw(const int*); // expected-error {{more lax}} virtual void y() throw(int*); // ok virtual void z() throw(long); // expected-error {{more lax}} }; #else void f() throw(int); // expected-error {{ISO C++17 does not allow}} expected-note {{use 'noexcept}} #endif } namespace dr127 { // dr127: yes __extension__ typedef __decltype(sizeof(0)) size_t; template struct A { A() { throw 0; } void *operator new(size_t, const char * = 0); void operator delete(void *, const char *) { T::error; } // expected-error 2{{no members}} void operator delete(void *) { T::error; } }; A *p = new A; // expected-note {{instantiat}} A *q = new ("") A; // expected-note {{instantiat}} } namespace dr128 { // dr128: yes enum E1 { e1 } x = e1; enum E2 { e2 } y = static_cast(x), z = static_cast(e1); } // dr129: dup 616 // dr130: na namespace dr131 { // dr131: yes const char *a_with_\u0e8c = "\u0e8c"; const char *b_with_\u0e8d = "\u0e8d"; const char *c_with_\u0e8e = "\u0e8e"; #if __cplusplus < 201103L // expected-error@-4 {{expected ';'}} expected-error@-2 {{expected ';'}} #endif } namespace dr132 { // dr132: no void f() { extern struct {} x; // ok extern struct S {} y; // FIXME: This is invalid. } static enum { E } e; } // dr133: dup 87 // dr134: na namespace dr135 { // dr135: yes struct A { A f(A a) { return a; } friend A g(A a) { return a; } static A h(A a) { return a; } }; } namespace dr136 { // dr136: 3.4 void f(int, int, int = 0); // expected-note {{previous declaration is here}} void g(int, int, int); // expected-note {{previous declaration is here}} struct A { friend void f(int, int = 0, int); // expected-error {{friend declaration specifying a default argument must be the only declaration}} friend void g(int, int, int = 0); // expected-error {{friend declaration specifying a default argument must be the only declaration}} friend void h(int, int, int = 0); // expected-error {{friend declaration specifying a default argument must be a definition}} friend void i(int, int, int = 0) {} // expected-note {{previous declaration is here}} friend void j(int, int, int = 0) {} operator int(); }; void i(int, int, int); // expected-error {{friend declaration specifying a default argument must be the only declaration}} void q() { j(A(), A()); // ok, has default argument } extern "C" void k(int, int, int, int); // expected-note {{previous declaration is here}} namespace NSA { struct A { friend void dr136::k(int, int, int, int = 0); // expected-error {{friend declaration specifying a default argument must be the only declaration}} \ // expected-note {{previous declaration is here}} }; } namespace NSB { struct A { friend void dr136::k(int, int, int = 0, int); // expected-error {{friend declaration specifying a default argument must be the only declaration}} }; } struct B { void f(int); // expected-note {{previous declaration is here}} }; struct C { friend void B::f(int = 0); // expected-error {{friend declaration specifying a default argument must be the only declaration}} }; } namespace dr137 { // dr137: yes extern void *p; extern const void *cp; extern volatile void *vp; extern const volatile void *cvp; int *q = static_cast(p); int *qc = static_cast(cp); // expected-error {{casts away qualifiers}} int *qv = static_cast(vp); // expected-error {{casts away qualifiers}} int *qcv = static_cast(cvp); // expected-error {{casts away qualifiers}} const int *cq = static_cast(p); const int *cqc = static_cast(cp); const int *cqv = static_cast(vp); // expected-error {{casts away qualifiers}} const int *cqcv = static_cast(cvp); // expected-error {{casts away qualifiers}} const volatile int *cvq = static_cast(p); const volatile int *cvqc = static_cast(cp); const volatile int *cvqv = static_cast(vp); const volatile int *cvqcv = static_cast(cvp); } namespace dr139 { // dr139: yes namespace example1 { typedef int f; // expected-note {{previous}} struct A { friend void f(A &); // expected-error {{different kind of symbol}} }; } namespace example2 { typedef int f; namespace N { struct A { friend void f(A &); operator int(); void g(A a) { int i = f(a); } // ok, f is typedef not friend function }; } } } namespace dr140 { // dr140: yes void f(int *const) {} // expected-note {{previous}} void f(int[3]) {} // expected-error {{redefinition}} void g(const int); void g(int n) { n = 2; } } namespace dr141 { // dr141: yes template void f(); template struct S { int n; }; struct A : S { template void f(); template struct S {}; } a; struct B : S {} b; void g() { a.f(); (void)a.S::n; // expected-error {{no member named 'n'}} #if __cplusplus < 201103L // expected-error@-2 {{ambiguous}} // expected-note@-11 {{lookup from the current scope}} // expected-note@-9 {{lookup in the object type}} #endif b.f(); // expected-error {{no member}} expected-error +{{}} (void)b.S::n; } template struct C { T t; void g() { t.f(); // expected-error {{use 'template'}} } void h() { (void)t.S::n; // ok } void i() { (void)t.S(); // ok! } }; void h() { C().h(); } // ok struct X { template void S(); }; void i() { C().i(); } // ok!! } namespace dr142 { // dr142: yes class B { // expected-note +{{here}} public: int mi; // expected-note +{{here}} static int si; // expected-note +{{here}} }; class D : private B { // expected-note +{{here}} }; class DD : public D { void f(); }; void DD::f() { mi = 3; // expected-error {{private base class}} expected-error {{private member}} si = 3; // expected-error {{private member}} B b_old; // expected-error {{private member}} dr142::B b; b.mi = 3; b.si = 3; B::si = 3; // expected-error {{private member}} dr142::B::si = 3; B *bp1_old = this; // expected-error {{private member}} expected-error {{private base class}} dr142::B *bp1 = this; // expected-error {{private base class}} B *bp2_old = (B*)this; // expected-error 2{{private member}} dr142::B *bp2 = (dr142::B*)this; bp2->mi = 3; } } namespace dr143 { // dr143: yes namespace A { struct X; } namespace B { void f(A::X); } namespace A { struct X { friend void B::f(X); }; } void g(A::X x) { f(x); // expected-error {{undeclared identifier 'f'}} } } namespace dr145 { // dr145: yes void f(bool b) { #if __cplusplus <= 201402L ++b; // expected-warning {{deprecated}} b++; // expected-warning {{deprecated}} #else ++b; // expected-error {{increment}} b++; // expected-error {{increment}} #endif } } namespace dr147 { // dr147: yes namespace example1 { template struct A { template A(T); }; // Per core issue 1435, this is ill-formed because A::A does not // name the injected-class-name. (A::A does, though.) template<> template<> A::A(int) {} // expected-error {{out-of-line constructor for 'A' cannot have template arguments}} template<> template<> A::A(float) {} } namespace example2 { struct A { A(); }; struct B : A { B(); }; A::A a1; // expected-error {{is a constructor}} B::A a2; } namespace example3 { template struct A { template A(T); static A a; }; template<> A::A(A::a); // expected-error {{is a constructor}} } } namespace dr148 { // dr148: yes struct A { int A::*p; }; int check1[__is_pod(int(A::*)) ? 1 : -1]; int check2[__is_pod(A) ? 1 : -1]; } // dr149: na namespace dr151 { // dr151: yes struct X {}; typedef int X::*p; #if __cplusplus < 201103L #define fold(x) (__builtin_constant_p(0) ? (x) : (x)) #else #define fold #endif int check[fold(p() == 0) ? 1 : -1]; #undef fold } namespace dr152 { // dr152: yes struct A { A(); // expected-note 0-2{{not viable}} explicit A(const A&); }; A a1 = A(); #if __cplusplus <= 201402L // expected-error@-2 {{no matching constructor}} #endif A a2((A())); A &f(); A a3 = f(); // expected-error {{no matching constructor}} A a4(f()); } // dr153: na namespace dr154 { // dr154: yes union { int a; }; // expected-error {{must be declared 'static'}} namespace { union { int b; }; } static union { int c; }; } namespace dr155 { // dr155: dup 632 struct S { int n; } s = { { 1 } }; // expected-warning {{braces around scalar initializer}} } // dr158 is in its own file. namespace dr159 { // dr159: 3.5 namespace X { void f(); } void f(); void dr159::f() {} // expected-warning {{extra qualification}} void dr159::X::f() {} } // dr160: na namespace dr161 { // dr161: yes class A { protected: struct B { int n; } b; // expected-note 2{{here}} static B bs; void f(); // expected-note {{here}} static void sf(); }; struct C : A {}; struct D : A { void g(C c) { (void)b.n; B b1; C::B b2; // ok, accessible as a member of A (void)&C::b; // expected-error {{protected}} (void)&C::bs; (void)c.b; // expected-error {{protected}} (void)c.bs; f(); sf(); c.f(); // expected-error {{protected}} c.sf(); A::f(); D::f(); A::sf(); C::sf(); D::sf(); } }; } namespace dr162 { // dr162: no struct A { char &f(char); static int &f(int); void g() { int &a = (&A::f)(0); // FIXME: expected-error {{could not be resolved}} char &b = (&A::f)('0'); // expected-error {{could not be resolved}} } }; int &c = (&A::f)(0); // FIXME: expected-error {{could not be resolved}} char &d = (&A::f)('0'); // expected-error {{could not be resolved}} } // dr163: na namespace dr164 { // dr164: yes void f(int); template int g(T t) { return f(t); } enum E { e }; int f(E); int k = g(e); } namespace dr165 { // dr165: no namespace N { struct A { friend struct B; }; void f() { void g(); } } // FIXME: dr1477 says this is ok, dr165 says it's ill-formed struct N::B {}; // FIXME: dr165 says this is ill-formed, but the argument in dr1477 says it's ok void N::g() {} } namespace dr166 { // dr166: yes namespace A { class X; } template int f(T t) { return t.n; } int g(A::X); template int h(T t) { return t.n; } // expected-error {{private}} int i(A::X); namespace A { class X { friend int f(X); friend int dr166::g(X); friend int h(X); friend int i(X); int n; // expected-note 2{{here}} }; int h(X x) { return x.n; } int i(X x) { return x.n; } } template int f(A::X); int g(A::X x) { return x.n; } template int h(A::X); // expected-note {{instantiation}} int i(A::X x) { return x.n; } // expected-error {{private}} } // dr167: sup 1012 namespace dr168 { // dr168: no extern "C" typedef int (*p)(); extern "C++" typedef int (*q)(); struct S { static int f(); }; p a = &S::f; // FIXME: this should fail. q b = &S::f; } namespace dr169 { // dr169: yes template struct A { int n; }; struct B { template struct C; template void f(); template static int n; // expected-error 0-1{{extension}} }; struct D : A, B { using A::n; using B::C; // expected-error {{using declaration cannot refer to a template specialization}} using B::f; // expected-error {{using declaration cannot refer to a template specialization}} using B::n; // expected-error {{using declaration cannot refer to a template specialization}} }; } namespace { // dr171: yes int dr171a; } int dr171b; // expected-note {{here}} namespace dr171 { extern "C" void dr171a(); extern "C" void dr171b(); // expected-error {{conflicts}} } namespace dr172 { // dr172: yes enum { zero }; int check1[-1 < zero ? 1 : -1]; enum { x = -1, y = (unsigned int)-1 }; int check2[sizeof(x) > sizeof(int) ? 1 : -1]; enum { a = (unsigned int)-1 / 2 }; int check3a[sizeof(a) == sizeof(int) ? 1 : -1]; int check3b[-a < 0 ? 1 : -1]; enum { b = (unsigned int)-1 / 2 + 1 }; int check4a[sizeof(b) == sizeof(unsigned int) ? 1 : -1]; int check4b[-b > 0 ? 1 : -1]; enum { c = (unsigned long)-1 / 2 }; int check5a[sizeof(c) == sizeof(long) ? 1 : -1]; int check5b[-c < 0 ? 1 : -1]; enum { d = (unsigned long)-1 / 2 + 1 }; int check6a[sizeof(d) == sizeof(unsigned long) ? 1 : -1]; int check6b[-d > 0 ? 1 : -1]; enum { e = (unsigned long long)-1 / 2 }; // expected-error 0-1{{extension}} int check7a[sizeof(e) == sizeof(long) ? 1 : -1]; // expected-error 0-1{{extension}} int check7b[-e < 0 ? 1 : -1]; enum { f = (unsigned long long)-1 / 2 + 1 }; // expected-error 0-1{{extension}} int check8a[sizeof(f) == sizeof(unsigned long) ? 1 : -1]; // expected-error 0-1{{extension}} int check8b[-f > 0 ? 1 : -1]; } namespace dr173 { // dr173: yes int check[('0' + 1 == '1' && '0' + 2 == '2' && '0' + 3 == '3' && '0' + 4 == '4' && '0' + 5 == '5' && '0' + 6 == '6' && '0' + 7 == '7' && '0' + 8 == '8' && '0' + 9 == '9') ? 1 : -1]; } // dr174: sup 1012 namespace dr175 { // dr175: yes struct A {}; // expected-note {{here}} struct B : private A {}; // expected-note {{constrained by private inheritance}} struct C : B { A a; // expected-error {{private}} dr175::A b; }; } namespace dr176 { // dr176: yes template class Y; template<> class Y { void f() { typedef Y A; // expected-note {{here}} typedef Y A; // expected-error {{different types ('Y' vs 'Y')}} } }; template struct Base {}; // expected-note 2{{found}} template struct Derived : public Base { void f() { typedef typename Derived::template Base A; typedef typename Derived::Base A; } }; template struct Derived; template struct Derived2 : Base, Base { typename Derived2::Base b; // expected-error {{found in multiple base classes}} typename Derived2::Base d; }; template class X { // expected-note {{here}} X *p1; X *p2; X *p3; dr176::X *p4; // expected-error {{requires template arguments}} }; } namespace dr177 { // dr177: yes struct B {}; struct A { A(A &); // expected-note 0-1{{not viable: expects an l-value}} A(const B &); // expected-note 0-1{{not viable: no known conversion from 'dr177::A' to}} }; B b; A a = b; #if __cplusplus <= 201402L // expected-error@-2 {{no viable constructor copying variable}} #endif struct C { C(C&); }; // expected-note {{not viable: no known conversion from 'dr177::D' to 'dr177::C &'}} struct D : C {}; struct E { operator D(); }; E e; C c = e; // expected-error {{no viable constructor copying variable of type 'dr177::D'}} } namespace dr178 { // dr178: yes int check[int() == 0 ? 1 : -1]; #if __cplusplus >= 201103L static_assert(int{} == 0, ""); struct S { int a, b; }; static_assert(S{1}.b == 0, ""); struct T { constexpr T() : n() {} int n; }; static_assert(T().n == 0, ""); struct U : S { constexpr U() : S() {} }; static_assert(U().b == 0, ""); #endif } namespace dr179 { // dr179: yes void f(); int n = &f - &f; // expected-error {{arithmetic on pointers to the function type 'void ()'}} } namespace dr180 { // dr180: yes template struct X : T, T::some_base { X() : T::some_type_that_might_be_T(), T::some_base() {} friend class T::some_class; void f() { enum T::some_enum e; } }; } namespace dr181 { // dr181: yes namespace X { template