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// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
// expected-no-diagnostics
// Example tuple implementation from the variadic templates proposal,
// ISO C++ committee document number N2080.
// Helper type traits
template<typename T>
struct add_reference {
typedef T &type;
};
template<typename T>
struct add_reference<T&> {
typedef T &type;
};
template<typename T>
struct add_const_reference {
typedef T const &type;
};
template<typename T>
struct add_const_reference<T&> {
typedef T &type;
};
template<typename T, typename U>
struct is_same {
static const bool value = false;
};
template<typename T>
struct is_same<T, T> {
static const bool value = true;
};
template<typename T>
class reference_wrapper {
T *ptr;
public:
reference_wrapper(T& t) : ptr(&t) { }
operator T&() const { return *ptr; }
};
template<typename T> reference_wrapper<T> ref(T& t) {
return reference_wrapper<T>(t);
}
template<typename T> reference_wrapper<const T> cref(const T& t) {
return reference_wrapper<const T>(t);
}
template<typename... Values> class tuple;
// Basis case: zero-length tuple
template<> class tuple<> { };
template<typename Head, typename... Tail>
class tuple<Head, Tail...> : private tuple<Tail...> {
typedef tuple<Tail...> inherited;
public:
tuple() { }
// implicit copy-constructor is okay
// Construct tuple from separate arguments.
tuple(typename add_const_reference<Head>::type v,
typename add_const_reference<Tail>::type... vtail)
: m_head(v), inherited(vtail...) { }
// Construct tuple from another tuple.
template<typename... VValues> tuple(const tuple<VValues...>& other)
: m_head(other.head()), inherited(other.tail()) { }
template<typename... VValues> tuple&
operator=(const tuple<VValues...>& other) {
m_head = other.head();
tail() = other.tail();
return *this;
}
typename add_reference<Head>::type head() { return m_head; }
typename add_reference<const Head>::type head() const { return m_head; }
inherited& tail() { return *this; }
const inherited& tail() const { return *this; }
protected:
Head m_head;
};
void test_tuple() {
tuple<> t0a;
tuple<> t0b(t0a);
t0a = t0b;
tuple<int> t1a;
tuple<int> t1b(17);
tuple<int> t1c(t1b);
t1a = t1b;
tuple<float> t1d(3.14159);
tuple<float> t1e(t1d);
t1d = t1e;
int i;
float f;
double d;
tuple<int*, float*, double*> t3a(&i, &f, &d);
}
// Creation functions
template<typename T>
struct make_tuple_result {
typedef T type;
};
template<typename T>
struct make_tuple_result<reference_wrapper<T> > {
typedef T& type;
};
template<typename... Values>
tuple<typename make_tuple_result<Values>::type...>
make_tuple(const Values&... values) {
return tuple<typename make_tuple_result<Values>::type...>(values...);
}
template<typename... Values>
tuple<Values&...> tie(Values&... values) {
return tuple<Values&...>(values...);
}
template<typename T> const T *addr(const T& ref) { return &ref; }
void test_creation_functions() {
int i;
float f;
double d;
const tuple<int, float&, const double&> *t3p = addr(make_tuple(i, ref(f), cref(d)));
const tuple<int&, float&, double&> *t3q = addr(tie(i, f, d));
}
// Helper classes
template<typename Tuple> struct tuple_size;
template<typename... Values> struct tuple_size<tuple<Values...> > {
static const int value = sizeof...(Values);
};
int check_tuple_size_0[tuple_size<tuple<> >::value == 0? 1 : -1];
int check_tuple_size_1[tuple_size<tuple<int>>::value == 1? 1 : -1];
int check_tuple_size_2[tuple_size<tuple<float, double>>::value == 2? 1 : -1];
int check_tuple_size_3[tuple_size<tuple<char, unsigned char, signed char>>::value == 3? 1 : -1];
template<int I, typename Tuple> struct tuple_element;
template<int I, typename Head, typename... Tail>
struct tuple_element<I, tuple<Head, Tail...> > {
typedef typename tuple_element<I-1, tuple<Tail...> >::type type;
};
template<typename Head, typename... Tail>
struct tuple_element<0, tuple<Head, Tail...> > {
typedef Head type;
};
int check_tuple_element_0[is_same<tuple_element<0, tuple<int&, float, double>>::type,
int&>::value? 1 : -1];
int check_tuple_element_1[is_same<tuple_element<1, tuple<int&, float, double>>::type,
float>::value? 1 : -1];
int check_tuple_element_2[is_same<tuple_element<2, tuple<int&, float, double>>::type,
double>::value? 1 : -1];
// Element access
template<int I, typename Tuple> class get_impl;
template<int I, typename Head, typename... Values>
class get_impl<I, tuple<Head, Values...> > {
typedef typename tuple_element<I-1, tuple<Values...> >::type Element;
typedef typename add_reference<Element>::type RJ;
typedef typename add_const_reference<Element>::type PJ;
typedef get_impl<I-1, tuple<Values...> > Next;
public:
static RJ get(tuple<Head, Values...>& t) { return Next::get(t.tail()); }
static PJ get(const tuple<Head, Values...>& t) { return Next::get(t.tail()); }
};
template<typename Head, typename... Values>
class get_impl<0, tuple<Head, Values...> > {
typedef typename add_reference<Head>::type RJ;
typedef typename add_const_reference<Head>::type PJ;
public:
static RJ get(tuple<Head, Values...>& t) { return t.head(); }
static PJ get(const tuple<Head, Values...>& t) { return t.head(); }
};
template<int I, typename... Values> typename add_reference<
typename tuple_element<I, tuple<Values...> >::type >::type
get(tuple<Values...>& t) {
return get_impl<I, tuple<Values...> >::get(t);
}
template<int I, typename... Values> typename add_const_reference<
typename tuple_element<I, tuple<Values...> >::type >::type
get(const tuple<Values...>& t) {
return get_impl<I, tuple<Values...> >::get(t);
}
void test_element_access(tuple<int*, float*, double*&> t3) {
int i;
float f;
double d;
get<0>(t3) = &i;
get<1>(t3) = &f;
get<2>(t3) = &d;
}
// Relational operators
inline bool operator==(const tuple<>&, const tuple<>&) { return true; }
template<typename T, typename... TTail, typename U, typename... UTail>
bool operator==(const tuple<T, TTail...>& t, const tuple<U, UTail...>& u) {
return t.head() == u.head() && t.tail() == u.tail();
}
template<typename... TValues, typename... UValues>
bool operator!=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
return !(t == u);
}
inline bool operator<(const tuple<>&, const tuple<>&) { return false; }
template<typename T, typename... TTail, typename U, typename... UTail>
bool operator<(const tuple<T, TTail...>& t, const tuple<U, UTail...>& u) {
return (t.head() < u.head() || (!(t.head() < u.head()) && t.tail() < u.tail()));
}
template<typename... TValues, typename... UValues>
bool operator>(const tuple<TValues...>& t, const tuple<UValues...>& u) {
return u < t;
}
template<typename... TValues, typename... UValues>
bool operator<=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
return !(u < t);
}
template<typename... TValues, typename... UValues>
bool operator>=(const tuple<TValues...>& t, const tuple<UValues...>& u) {
return !(t < u);
}
void test_relational_operators(tuple<int*, float*, double*> t3) {
(void)(t3 == t3);
(void)(t3 != t3);
(void)(t3 < t3);
(void)(t3 <= t3);
(void)(t3 >= t3);
(void)(t3 > t3);
};
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