p4-1y.cpp source code [clang_source_code/test/CXX/expr/expr.prim/expr.prim.lambda/p4-1y.cpp]

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	}

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