1 // RUN: %clang_cc1 -fsyntax-only -std=c++1y %s -verify 2 3 int a; 4 int &b = [] (int &r) -> decltype(auto) { return r; } (a); 5 int &c = [] (int &r) -> decltype(auto) { return (r); } (a); 6 int &d = [] (int &r) -> auto & { return r; } (a); 7 int &e = [] (int &r) -> auto { return r; } (a); // expected-error {{cannot bind to a temporary}} 8 int &f = [] (int r) -> decltype(auto) { return r; } (a); // expected-error {{cannot bind to a temporary}} 9 int &g = [] (int r) -> decltype(auto) { return (r); } (a); // expected-warning {{reference to stack}} 10 11 12 int test_explicit_auto_return() 13 { 14 struct X {}; 15 auto L = [](auto F, auto a) { return F(a); }; 16 auto M = [](auto a) -> auto { return a; }; // OK 17 auto MRef = [](auto b) -> auto& { return b; }; //expected-warning{{reference to stack}} 18 auto MPtr = [](auto c) -> auto* { return &c; }; //expected-warning{{address of stack}} 19 auto MDeclType = [](auto&& d) -> decltype(auto) { return static_cast<decltype(d)>(d); }; //OK 20 M(3); 21 22 auto &&x = MDeclType(X{}); 23 auto &&x1 = M(X{}); 24 auto &&x2 = MRef(X{});//expected-note{{in instantiation of}} 25 auto &&x3 = MPtr(X{}); //expected-note{{in instantiation of}} 26 return 0; 27 } 28 29 int test_implicit_auto_return() 30 { 31 { 32 auto M = [](auto a) { return a; }; 33 struct X {}; 34 X x = M(X{}); 35 36 } 37 } 38 39 int test_multiple_returns() { 40 auto M = [](auto a) { 41 bool k; 42 if (k) 43 return a; 44 else 45 return 5; //expected-error{{deduced as 'int' here}} 46 }; 47 M(3); // OK 48 M('a'); //expected-note{{in instantiation of}} 49 return 0; 50 } 51 int test_no_parameter_list() 52 { 53 static int si = 0; 54 auto M = [] { return 5; }; // OK 55 auto M2 = [] -> auto&& { return si; }; // expected-error{{lambda requires '()'}} 56 M(); 57 } 58 59 int test_conditional_in_return() { 60 auto Fac = [](auto f, auto n) { 61 return n <= 0 ? n : f(f, n - 1) * n; 62 }; 63 // FIXME: this test causes a recursive limit - need to error more gracefully. 64 //Fac(Fac, 3); 65 66 }
