llvm-for-llvmta/tools/clang/test/CXX/expr/expr.prim/expr.prim.lambda/p4-1y.cpp

66 lines
1.9 KiB
C++

// RUN: %clang_cc1 -fsyntax-only -std=c++1y %s -verify
int a;
int &b = [] (int &r) -> decltype(auto) { return r; } (a);
int &c = [] (int &r) -> decltype(auto) { return (r); } (a);
int &d = [] (int &r) -> auto & { return r; } (a);
int &e = [] (int &r) -> auto { return r; } (a); // expected-error {{cannot bind to a temporary}}
int &f = [] (int r) -> decltype(auto) { return r; } (a); // expected-error {{cannot bind to a temporary}}
int &g = [] (int r) -> decltype(auto) { return (r); } (a); // expected-warning {{reference to stack}}
int test_explicit_auto_return()
{
struct X {};
auto L = [](auto F, auto a) { return F(a); };
auto M = [](auto a) -> auto { return a; }; // OK
auto MRef = [](auto b) -> auto& { return b; }; //expected-warning{{reference to stack}}
auto MPtr = [](auto c) -> auto* { return &c; }; //expected-warning{{address of stack}}
auto MDeclType = [](auto&& d) -> decltype(auto) { return static_cast<decltype(d)>(d); }; //OK
M(3);
auto &&x = MDeclType(X{});
auto &&x1 = M(X{});
auto &&x2 = MRef(X{});//expected-note{{in instantiation of}}
auto &&x3 = MPtr(X{}); //expected-note{{in instantiation of}}
return 0;
}
int test_implicit_auto_return()
{
{
auto M = [](auto a) { return a; };
struct X {};
X x = M(X{});
}
}
int test_multiple_returns() {
auto M = [](auto a) {
bool k;
if (k)
return a;
else
return 5; //expected-error{{deduced as 'int' here}}
};
M(3); // OK
M('a'); //expected-note{{in instantiation of}}
return 0;
}
int test_no_parameter_list()
{
static int si = 0;
auto M = [] { return 5; }; // OK
auto M2 = [] -> auto&& { return si; }; // expected-error{{lambda requires '()'}}
M();
}
int test_conditional_in_return() {
auto Fac = [](auto f, auto n) {
return n <= 0 ? n : f(f, n - 1) * n;
};
// FIXME: this test causes a recursive limit - need to error more gracefully.
//Fac(Fac, 3);
}