llvm-project/clang/test/CXX/expr/expr.prim/expr.prim.lambda/p5-generic-lambda-1y.cpp

132 lines
3.1 KiB
C++

// RUN: %clang_cc1 -fsyntax-only -verify %s -std=c++1y -DCXX1Y
namespace test_factorial {
auto Fact = [](auto Self, unsigned n) -> unsigned {
return !n ? 1 : Self(Self, n - 1) * n;
};
auto six = Fact(Fact, 3);
}
namespace overload_generic_lambda {
template <class F1, class F2> struct overload : F1, F2 {
using F1::operator();
using F2::operator();
overload(F1 f1, F2 f2) : F1(f1), F2(f2) { }
};
auto NumParams = [](auto Self, auto h, auto ... rest) -> unsigned {
return 1 + Self(Self, rest...);
};
auto Base = [](auto Self, auto h) -> unsigned {
return 1;
};
overload<decltype(Base), decltype(NumParams)> O(Base, NumParams);
int num_params = O(O, 5, 3, "abc", 3.14, 'a');
}
namespace overload_generic_lambda_return_type_deduction {
template <class F1, class F2> struct overload : F1, F2 {
using F1::operator();
using F2::operator();
overload(F1 f1, F2 f2) : F1(f1), F2(f2) { }
};
auto NumParams = [](auto Self, auto h, auto ... rest) {
return 1 + Self(Self, rest...);
};
auto Base = [](auto Self, auto h) {
return 1;
};
overload<decltype(Base), decltype(NumParams)> O(Base, NumParams);
int num_params = O(O, 5, 3, "abc", 3.14, 'a');
}
namespace test_standard_p5 {
// FIXME: This test should eventually compile without an explicit trailing return type
auto glambda = [](auto a, auto&& b) ->bool { return a < b; };
bool b = glambda(3, 3.14); // OK
}
namespace test_deduction_failure {
int test() {
auto g = [](auto *a) { //expected-note{{candidate template ignored}}
return a;
};
struct X { };
X *x;
g(x);
g(3); //expected-error{{no matching function}}
return 0;
}
}
namespace test_instantiation_or_sfinae_failure {
int test2() {
{
auto L = [](auto *a) {
return (*a)(a); }; //expected-error{{called object type 'double' is not a function}}
double d;
L(&d); //expected-note{{in instantiation of}}
auto M = [](auto b) { return b; };
L(&M); // ok
}
{
auto L = [](auto *a) ->decltype (a->foo()) { //expected-note2{{candidate template ignored:}}
return (*a)(a); };
double d;
L(&d); //expected-error{{no matching function for call}}
auto M = [](auto b) { return b; };
L(&M); //expected-error{{no matching function for call}}
}
return 0;
}
}
namespace test_misc {
auto GL = [](auto a, decltype(a) b) //expected-note{{candidate function}}
-> int { return a + b; };
void test() {
struct X { };
GL(3, X{}); //expected-error{{no matching function}}
}
void test2() {
auto l = [](auto *a) -> int {
(*a)(a); return 0; }; //expected-error{{called object type 'double' is not a function}}
l(&l);
double d;
l(&d); //expected-note{{in instantiation of}}
}
}
namespace nested_lambdas {
int test() {
auto L = [](auto a) {
return [=](auto b) {
return a + b;
};
};
}
auto get_lambda() {
return [](auto a) {
return a;
};
};
int test2() {
auto L = get_lambda();
L(3);
}
}