================
@@ -0,0 +1,226 @@
+// RUN: %clang_cc1 %s -verify
+template <typename...> struct TypeList;
+
+// === Check results of the builtin.
+template <class>
+struct TemplateWrapper {
+ static_assert(__is_same( // expected-error {{static assertion contains an
unexpanded parameter pack}}
+ TypeList<__builtin_dedup_pack<int, int*, int, double, float>>,
+ TypeList<int, int*, double, float>));
+};
+
+template <template<typename ...> typename Templ, typename ...Types>
+struct Dependent {
+ using empty_list = Templ<__builtin_dedup_pack<>...>;
+ using same = Templ<__builtin_dedup_pack<Types...>...>;
+ using twice = Templ<__builtin_dedup_pack<Types..., Types...>...>;
+ using dep_only_types = TypeList<__builtin_dedup_pack<Types...>...>;
+ using dep_only_template = Templ<__builtin_dedup_pack<int, double, int>...>;
+};
+
+// Check the reverse condition to make sure we see an error and not
accidentally produced dependent expression.
+static_assert(!__is_same(Dependent<TypeList>::empty_list, TypeList<>)); //
expected-error {{static assertion failed}}
+static_assert(!__is_same(Dependent<TypeList>::same, TypeList<>)); //
expected-error {{static assertion failed}}
+static_assert(!__is_same(Dependent<TypeList>::twice, TypeList<>)); //
expected-error {{static assertion failed}}
+static_assert(!__is_same(Dependent<TypeList>::dep_only_types, TypeList<>)); //
expected-error {{static assertion failed}}
+static_assert(!__is_same(Dependent<TypeList>::dep_only_template, TypeList<int,
double>)); // expected-error {{static assertion failed}}
+static_assert(!__is_same(Dependent<TypeList, int*, double*, int*>::empty_list,
TypeList<>)); // expected-error {{static assertion failed}}
+static_assert(!__is_same(Dependent<TypeList, int*, double*, int*>::same,
TypeList<int*, double*>)); // expected-error {{static assertion failed}}
+static_assert(!__is_same(Dependent<TypeList, int*, double*, int*>::twice,
TypeList<int*, double*>)); // expected-error {{static assertion failed}}
+static_assert(!__is_same(Dependent<TypeList, int*, double*,
int*>::dep_only_types, TypeList<int*, double*>)); // expected-error {{static
assertion failed}}
+static_assert(!__is_same(Dependent<TypeList, int*, double*,
int*>::dep_only_template, TypeList<int, double>)); // expected-error {{static
assertion failed}}
+
+
+template <class ...T>
+using Twice = TypeList<T..., T...>;
+
+template <class>
+struct TwiceTemplateWrapper {
+ static_assert(!__is_same(Twice<__builtin_dedup_pack<int, double, int>...>,
TypeList<int, double, int, double>)); // expected-error {{static assertion
failed}}
+
+};
+template struct TwiceTemplateWrapper<int>; // expected-note {{in instantiation
of template class 'TwiceTemplateWrapper<int>' requested here}}
+
+template <int...> struct IntList;
+// Wrong kinds of template arguments.
+template <class> struct IntListTemplateWrapper {
+ IntList<__builtin_dedup_pack<int>...>* wrong_template; // expected-error
{{template argument for non-type template parameter must be an expression}}
+ // expected-note@-4
{{template parameter is declared here}}
+ TypeList<__builtin_dedup_pack<1, 2, 3>...>* wrong_template_args; //
expected-error {{template argument for template type parameter must be a type}}
+ //
expected-note@* {{template parameter from hidden source}}
+ __builtin_dedup_pack<> not_enough_args; // expected-error {{data member type
contains an unexpanded parameter pack}}
+ // expected-note@* {{template
declaration from hidden source}}
+ __builtin_dedup_pack missing_template_args; // expected-error {{use of
template '__builtin_dedup_pack' requires template arguments}}
+};
+
+// Make sure various canonical / non-canonical type representations do not
affect results
+// of the deduplication and the qualifiers do end up creating different types
when C++ requires it.
+using Int = int;
+using CInt = const Int;
+using IntArray = Int[10];
+using CIntArray = Int[10];
+using IntPtr = int*;
+using CIntPtr = const int*;
+
+template <class>
+struct Foo {
+ static_assert(
+ !__is_same( // expected-error {{static assertion failed}}
+ // expected-note@* {{in instantiation of template class
'Foo<int>'}}
+ TypeList<__builtin_dedup_pack<
+ Int, int,
+ const int, const Int, CInt, const CInt,
+ IntArray, Int[10], int[10],
+ const IntArray, const int[10], CIntArray, const CIntArray,
+ IntPtr, int*,
+ const IntPtr, int* const,
+ CIntPtr, const int*,
+ const IntPtr*, int*const*,
+ CIntPtr*, const int**,
+ const CIntPtr*, const int* const*
+ >...>,
+ TypeList<int, const int, int[10], const int [10], int*, int* const,
const int*, int*const *, const int**, const int*const*>),
+ "");
+};
+
+template struct Foo<int>;
+
+// === Show an error when packs are used in non-template contexts.
+static_assert(!__is_same(TypeList<__builtin_dedup_pack<int>...>,
TypeList<int>)); // expected-error {{outside}}
+// Non-dependent uses in template are fine, though.
+template <class T>
+struct NonDepInTemplate {
+ static_assert(!__is_same(TypeList<__builtin_dedup_pack<int>...>,
TypeList<int>)); // expected-error {{static assertion failed}}
+};
+template struct NonDepInTemplate<int>; // expected-note {{requested here}}
+
+template <template<class...> class T = __builtin_dedup_pack> // expected-error
{{use of template '__builtin_dedup_pack' requires template arguments}}
+ //
expected-note@* {{template declaration from hidden source}}
+struct UseAsTemplate;
+template <template<class...> class>
+struct AcceptsTemplateArg;
+template <class>
+struct UseAsTemplateWrapper {
+ AcceptsTemplateArg<__builtin_dedup_pack>* a; // expected-error {{use of
template '__builtin_dedup_pack' requires template arguments}}
+ // expected-note@* {{template
declaration from hidden source}}
+};
+
+// === Check how expansions in various contexts behave.
+// The following cases are not supported yet, should produce an error.
+template <class... T>
+struct DedupBases : __builtin_dedup_pack<T...>... {};
+struct Base1 {
+ int a1;
+};
+struct Base2 {
+ int a2;
+};
+static_assert(DedupBases<Base1, Base1, Base2, Base1, Base2, Base2>{1, 2}.a1 !=
1); // expected-error {{static assertion failed}} \
+
// expected-note {{}}
+static_assert(DedupBases<Base1, Base1, Base2, Base1, Base2, Base2>{1, 2}.a2 !=
2); // expected-error {{static assertion failed}} \
+
// expected-note {{}}
+
+template <class ...T>
+constexpr int dedup_params(__builtin_dedup_pack<T...>... as) {
+ return (as + ...);
+}
+static_assert(dedup_params<int, int, short, int, short, short>(1, 2)); //
expected-error {{no matching function}} \
+ //
expected-note@-3 {{expansions of '__builtin_dedup_pack' are not supported here}}
+
+template <class ...T>
+constexpr int
dedup_params_into_type_list(TypeList<__builtin_dedup_pack<T...>...> *, T... as)
{
+ return (as + ...);
+}
+static_assert(dedup_params_into_type_list(static_cast<TypeList<int,short,long>*>(nullptr),
1, short(1), 1, 1l, 1l) != 5); // expected-error {{static assertion failed}} \
+
// expected-note {{expression
evaluates}}
+
+template <class T, __builtin_dedup_pack<T, int>...> // expected-error
2{{expansions of '__builtin_dedup_pack' are not supported here}}
+struct InTemplateParams {};
+InTemplateParams<int> itp1;
+InTemplateParams<int, 1, 2, 3, 4, 5> itp2;
+
+template <class T>
+struct DeepTemplateParams {
+ template <__builtin_dedup_pack<T, int>...> // expected-error {{expansions of
'__builtin_dedup_pack' are not supported here}}
+ struct Templ {};
+};
+DeepTemplateParams<int>::Templ<> dtp1; // expected-note {{requested here}} \
+ // expected-error {{no template named
'Templ'}}
+
+
+template <class ...T>
+struct MemInitializers : T... {
+ MemInitializers() : __builtin_dedup_pack<T...>()... {} // expected-error
2{{expansions of '__builtin_dedup_pack' are not supported here.}}
+};
+MemInitializers<> mi1; // expected-note {{in instantiation of member function}}
+MemInitializers<Base1, Base2> mi2; // expected-note {{in instantiation of
member function}}
+
+template <class ...T>
+constexpr int dedup_in_expressions() {
+ // counts the number of unique Ts.
+ return ((1 + __builtin_dedup_pack<T...>()) + ...); // expected-error
{{expansions of '__builtin_dedup_pack' are not supported here.}} \
+ // expected-note@+3 {{in
instantiation of function template specialization}}
+}
+static_assert(dedup_in_expressions<int, int, short, double, int, short,
double, int>() == 3); // expected-error {{not an integral constant expression}}
+
+template <class ...T>
+void in_exception_spec() throw(__builtin_dedup_pack<T...>...); //
expected-error{{C++17 does not allow dynamic exception specifications}} \
+ //
expected-note {{use 'noexcept}} \
+ //
expected-error{{expansions of '__builtin_dedup_pack' are not supported here.}}
+
+void test_in_exception_spec() {
+ in_exception_spec<int, double, int>(); // expected-note {{instantiation of
exception specification}}
+}
+
+template <class ...T>
+constexpr bool in_type_trait = __is_trivially_constructible(int,
__builtin_dedup_pack<T...>...); // expected-error{{expansions of
'__builtin_dedup_pack' are not supported here.}}
+
+static_assert(in_type_trait<int, int, int>); // expected-note{{in
instantiation of variable template specialization}}
+
+template <class ...T>
+struct InFriends {
+ friend __builtin_dedup_pack<T>...; // expected-warning {{variadic 'friend'
declarations are a C++2c extension}} \
+ // expected-error 2 {{expansions of
'__builtin_dedup_pack' are not supported here.}} \
+ // expected-note@* 2 {{in instantiation
of template class}}
+
+};
+struct Friend1 {};
+struct Friend2 {};
+InFriends<> if1;
+InFriends<Friend1, Friend2> if2;
+
+template <class ...T>
+struct InUsingDecl {
+ using __builtin_dedup_pack<T...>::func...; // expected-error 2 {{expansions
of '__builtin_dedup_pack' are not supported here.}}
+};
+struct WithFunc1 { void func(); };
+struct WithFunc2 { void func(int); };
+InUsingDecl<> iu1; // expected-note {{in instantiation of template class}}
+InUsingDecl<WithFunc1, WithFunc2> iu2; // expected-note {{in instantiation of
template class}}
+
+// Note: produces parsing errors and does not construct pack indexing.
+// Keep this commented out until the parser supports this.
+//
+// template <class ...T>
+// struct InPackIndexing {
+//
+// using type = __builtin_dedup_pack<T...>...[0];
+// };
+// static_assert(__is_same(InPackIndexing<int, int>, int));
+
+template <class ...T>
+struct LambdaInitCaptures {
+ static constexpr int test() {
+ [...foos=__builtin_dedup_pack<T...>()]{}; // expected-warning
{{initialized lambda pack captures are a C++20 extension}} \
----------------
ilya-biryukov wrote:
Addressed in 26d4e56be81adbaa8aeed7f5cde39b779d959fc3, thanks for bringing this
up.
https://github.com/llvm/llvm-project/pull/106730
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