llvm-project/clang/test/SemaCXX/vartemplate-lambda.cpp

37 lines
1.2 KiB
C++

// RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify %s
template <class> auto fn0 = [] {};
template <typename> void foo0() { fn0<char>(); }
template<typename T> auto fn1 = [](auto a) { return a + T(1); };
template<typename T> auto v1 = [](int a = T(1)) { return a; }();
struct S {
template<class T>
static constexpr T t = [](int f = T(7)){return f;}(); // expected-error{{constexpr variable 't<int>' must be initialized by a constant expression}} expected-error{{a lambda expression may not appear inside of a constant expression}} expected-note{{cannot be used in a constant expression}}
};
template <typename X>
int foo2() {
X a = 0x61;
fn1<char>(a);
(void)v1<int>;
(void)S::t<int>; // expected-note{{in instantiation of static data member 'S::t<int>' requested here}}
return 0;
}
template<class C>
int foo3() {
C::m1(); // expected-error{{type 'long long' cannot be used prior to '::' because it has no members}}
return 1;
}
template<class C>
auto v2 = [](int a = foo3<C>()){}; // expected-note{{in instantiation of function template specialization 'foo3<long long>' requested here}}
int main() {
v2<long long>(); // This line causes foo3<long long> to be instantiated.
v2<long long>(2); // This line does not.
foo2<int>();
}