#include <cstddef>
#include <utility>
+#ifndef __has_feature
+#define LLVM_DEFINED_HAS_FEATURE
+#define __has_feature(x) 0
+#endif
+
// This is actually the conforming implementation which works with abstract
// classes. However, enough compilers have trouble with it that most will use
// the one in boost/type_traits/object_traits.hpp. This implementation actually
// is_class<> metafunction due to Paul Mensonides (leavings@attbi.com). For
// more details:
// http://groups.google.com/groups?hl=en&selm=000001c1cc83%24e154d5e0%247772e50c%40c161550a&rnum=1
- public:
- enum { value = sizeof(char) == sizeof(dont_use::is_class_helper<T>(0)) };
+public:
+ static const bool value =
+ sizeof(char) == sizeof(dont_use::is_class_helper<T>(0));
};
/// type can be copied around with memcpy instead of running ctors etc.
template <typename T>
struct isPodLike {
+#if __has_feature(is_trivially_copyable)
+ // If the compiler supports the is_trivially_copyable trait use it, as it
+ // matches the definition of isPodLike closely.
+ static const bool value = __is_trivially_copyable(T);
+#else
// If we don't know anything else, we can (at least) assume that all non-class
// types are PODs.
static const bool value = !is_class<T>::value;
+#endif
};
// std::pair's are pod-like if their elements are.
template<typename T, typename U>
struct isPodLike<std::pair<T, U> > {
- static const bool value = isPodLike<T>::value & isPodLike<U>::value;
+ static const bool value = isPodLike<T>::value && isPodLike<U>::value;
};
template <typename T>
struct is_integral : is_integral_impl<T> {};
+/// \brief Metafunction to remove reference from a type.
+template <typename T> struct remove_reference { typedef T type; };
+template <typename T> struct remove_reference<T&> { typedef T type; };
+
+/// \brief Metafunction that determines whether the given type is a pointer
+/// type.
+template <typename T> struct is_pointer : false_type {};
+template <typename T> struct is_pointer<T*> : true_type {};
+template <typename T> struct is_pointer<T* const> : true_type {};
+template <typename T> struct is_pointer<T* volatile> : true_type {};
+template <typename T> struct is_pointer<T* const volatile> : true_type {};
+
/// \brief Metafunction that determines whether the given type is either an
/// integral type or an enumeration type.
///
/// Note that this accepts potentially more integral types than we whitelist
-/// above for is_integral, it should accept essentially anything the compiler
-/// believes is an integral type.
+/// above for is_integral because it is based on merely being convertible
+/// implicitly to an integral type.
template <typename T> class is_integral_or_enum {
+ // Provide an overload which can be called with anything implicitly
+ // convertible to an unsigned long long. This should catch integer types and
+ // enumeration types at least. We blacklist classes with conversion operators
+ // below.
+ static double check_int_convertible(unsigned long long);
+ static char check_int_convertible(...);
- // Form a return type that can only be instantiated with an integral or enum
- // types (or with nullptr_t in C++11).
- template <typename U, U u = U()> struct check1_return_type { char c[2]; };
- template <typename U> static check1_return_type<U> checker1(U*);
- template <typename U> static char checker1(...);
-
- // Form a return type that can only be instantiated with nullptr_t in C++11
- // mode. It's harmless in C++98 mode, but this allows us to filter nullptr_t
- // when building in C++11 mode without having to detect that mode for each
- // different compiler.
- struct nonce {};
- template <typename U, nonce* u = U()>
- struct check2_return_type { char c[2]; };
- template <typename U> static check2_return_type<U> checker2(U*);
- template <typename U> static char checker2(...);
+ typedef typename remove_reference<T>::type UnderlyingT;
+ static UnderlyingT &nonce_instance;
public:
- enum {
- value = (sizeof(char) != sizeof(checker1<T>(0)) &&
- sizeof(char) == sizeof(checker2<T>(0)))
- };
+ static const bool
+ value = (!is_class<UnderlyingT>::value && !is_pointer<UnderlyingT>::value &&
+ !is_same<UnderlyingT, float>::value &&
+ !is_same<UnderlyingT, double>::value &&
+ sizeof(char) != sizeof(check_int_convertible(nonce_instance)));
};
-/// \brief Metafunction that determines whether the given type is a pointer
-/// type.
-template <typename T> struct is_pointer : false_type {};
-template <typename T> struct is_pointer<T*> : true_type {};
-
// enable_if_c - Enable/disable a template based on a metafunction
template<bool Cond, typename T = void>
struct enable_if_c {
}
+#ifdef LLVM_DEFINED_HAS_FEATURE
+#undef __has_feature
+#endif
+
#endif