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// RUN: %clang_cc1 -fsyntax-only -std=c++17 -verify %s
// RUN: %clang_cc1 -fsyntax-only -std=c++20 -verify %s
// expected-no-diagnostics
namespace std {
template<typename Signature> class function;
template<typename R, typename... Args> class invoker_base {
public:
virtual ~invoker_base() { }
virtual R invoke(Args...) = 0;
virtual invoker_base* clone() = 0;
};
template<typename F, typename R, typename... Args>
class functor_invoker : public invoker_base<R, Args...> {
public:
explicit functor_invoker(const F& f) : f(f) { }
R invoke(Args... args) { return f(args...); }
functor_invoker* clone() { return new functor_invoker(f); }
private:
F f;
};
template<typename R, typename... Args>
class function<R (Args...)> {
public:
typedef R result_type;
function() : invoker (0) { }
function(const function& other) : invoker(0) {
if (other.invoker)
invoker = other.invoker->clone();
}
template<typename F> function(const F& f) : invoker(0) {
invoker = new functor_invoker<F, R, Args...>(f);
}
~function() {
if (invoker)
delete invoker;
}
function& operator=(const function& other) {
function(other).swap(*this);
return *this;
}
template<typename F>
function& operator=(const F& f) {
function(f).swap(*this);
return *this;
}
void swap(function& other) {
invoker_base<R, Args...>* tmp = invoker;
invoker = other.invoker;
other.invoker = tmp;
}
result_type operator()(Args... args) const {
return invoker->invoke(args...);
}
private:
invoker_base<R, Args...>* invoker;
};
}
template<typename TemplateParam>
struct Problem {
template<typename FunctionTemplateParam>
constexpr int FuncAlign(int param = alignof(FunctionTemplateParam));
template<typename FunctionTemplateParam>
constexpr int FuncSizeof(int param = sizeof(FunctionTemplateParam));
template<typename FunctionTemplateParam>
constexpr int FuncAlign2(int param = alignof(TemplateParam));
template<typename FunctionTemplateParam>
constexpr int FuncSizeof2(int param = sizeof(TemplateParam));
};
template<typename TemplateParam>
struct Problem<TemplateParam*> {
template<typename FunctionTemplateParam>
constexpr int FuncAlign(int param = alignof(FunctionTemplateParam));
template<typename FunctionTemplateParam>
constexpr int FuncSizeof(int param = sizeof(FunctionTemplateParam));
template<typename FunctionTemplateParam>
constexpr int FuncAlign2(int param = alignof(TemplateParam));
template<typename FunctionTemplateParam>
constexpr int FuncSizeof2(int param = sizeof(TemplateParam));
};
template<typename TemplateParam>
template<typename FunctionTemplateParam>
constexpr int Problem<TemplateParam*>::FuncAlign(int param) {
return 2U*param;
}
template<typename TemplateParam>
template<typename FunctionTemplateParam>
constexpr int Problem<TemplateParam*>::FuncSizeof(int param) {
return 2U*param;
}
template<typename TemplateParam>
template<typename FunctionTemplateParam>
constexpr int Problem<TemplateParam*>::FuncAlign2(int param) {
return 2U*param;
}
template<typename TemplateParam>
template<typename FunctionTemplateParam>
constexpr int Problem<TemplateParam*>::FuncSizeof2(int param) {
return 2U*param;
}
template <>
template<typename FunctionTemplateParam>
constexpr int Problem<int>::FuncAlign(int param) {
return param;
}
template <>
template<typename FunctionTemplateParam>
constexpr int Problem<int>::FuncSizeof(int param) {
return param;
}
template <>
template<typename FunctionTemplateParam>
constexpr int Problem<int>::FuncAlign2(int param) {
return param;
}
template <>
template<typename FunctionTemplateParam>
constexpr int Problem<int>::FuncSizeof2(int param) {
return param;
}
void foo() {
Problem<int> p = {};
static_assert(p.FuncAlign<char>() == alignof(char));
static_assert(p.FuncSizeof<char>() == sizeof(char));
static_assert(p.FuncAlign2<char>() == alignof(int));
static_assert(p.FuncSizeof2<char>() == sizeof(int));
Problem<short*> q = {};
static_assert(q.FuncAlign<char>() == 2U * alignof(char));
static_assert(q.FuncSizeof<char>() == 2U * sizeof(char));
static_assert(q.FuncAlign2<char>() == 2U *alignof(short));
static_assert(q.FuncSizeof2<char>() == 2U * sizeof(short));
}
template <typename T>
class A {
public:
void run(
std::function<void(T&)> f1 = [](auto&&) {},
std::function<void(T&)> f2 = [](auto&&) {});
private:
class Helper {
public:
explicit Helper(std::function<void(T&)> f2) : f2_(f2) {}
std::function<void(T&)> f2_;
};
};
template <typename T>
void A<T>::run(std::function<void(T&)> f1,
std::function<void(T&)> f2) {
Helper h(f2);
}
struct B {};
int main() {
A<B> a;
a.run([&](auto& l) {});
return 0;
}
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