xref: /llvm-project/clang/test/SemaCXX/vartemplate-lambda.cpp (revision 3eeed79946124a8f67a89bb950a1e510369dcdf9)
1 // RUN: %clang_cc1 -std=c++14 -fsyntax-only -verify %s
2 
__anonc90add910102null3 template <class> auto fn0 = [] {};
foo0()4 template <typename> void foo0() { fn0<char>(); }
5 
__anonc90add910202(auto a) 6 template<typename T> auto fn1 = [](auto a) { return a + T(1); };
__anonc90add910302(int a = T()) 7 template<typename T> auto v1 = [](int a = T()) { return a; }();
8 // expected-error@-1{{cannot initialize a parameter of type 'int' with an rvalue of type 'int *'}}
9 // expected-note@-2{{in instantiation of default function argument expression for 'operator()<int *>' required here}}
10 // expected-note@-3{{passing argument to parameter 'a' here}}
11 
12 struct S {
13   template<class T>
__anonc90add910402S14   static constexpr T t = [](int f = T(7)){return f;}(); // expected-error{{constexpr variable 't<int>' must be initialized by a constant expression}} expected-note{{cannot be used in a constant expression}}
15 };
16 
17 template <typename X>
foo2()18 int foo2() {
19   X a = 0x61;
20   fn1<char>(a);
21   (void)v1<int>;
22   (void)v1<int *>; // expected-note{{in instantiation of variable template specialization 'v1' requested here}}
23   (void)S::t<int>; // expected-note{{in instantiation of static data member 'S::t<int>' requested here}}
24   return 0;
25 }
26 
27 template<class C>
foo3()28 int foo3() {
29   C::m1(); // expected-error{{type 'long long' cannot be used prior to '::' because it has no members}}
30   return 1;
31 }
32 
33 template<class C>
__anonc90add910502(int a = foo3<C>())34 auto v2 = [](int a = foo3<C>()){};  // expected-note{{in instantiation of function template specialization 'foo3<long long>' requested here}}
35 
main()36 int main() {
37   v2<long long>();  // This line causes foo3<long long> to be instantiated.
38   v2<long long>(2); // This line does not.
39   foo2<int>();
40 }
41