//===- llvm/Support/type_traits.h - Simplfied type traits -------*- C++ -*-===//
-//
+//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
//===----------------------------------------------------------------------===//
//
// This file provides a template class that determines if a type is a class or
// not. The basic mechanism, based on using the pointer to member function of
-// a zero argument to a function was "boosted" from the boost type_traits
-// library. See http://www.boost.org/ for all the gory details.
+// a zero argument to a function was "boosted" from the boost type_traits
+// library. See http://www.boost.org/ for all the gory details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_TYPE_TRAITS_H
#define LLVM_SUPPORT_TYPE_TRAITS_H
+#include "llvm/Support/DataTypes.h"
+#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
// works with VC7.0, but other interactions seem to fail when we use it.
namespace llvm {
-
+
namespace dont_use
{
// These two functions should never be used. They are helpers to
- // the is_class template below. They cannot be located inside
+ // the is_class template below. They cannot be located inside
// is_class because doing so causes at least GCC to think that
// the value of the "value" enumerator is not constant. Placing
- // them out here (for some strange reason) allows the sizeof
+ // them out here (for some strange reason) allows the sizeof
// operator against them to magically be constant. This is
// important to make the is_class<T>::value idiom zero cost. it
- // evaluates to a constant 1 or 0 depending on whether the
+ // evaluates to a constant 1 or 0 depending on whether the
// parameter T is a class or not (respectively).
- template<typename T> char is_class_helper(void(T::*)(void));
+ template<typename T> char is_class_helper(void(T::*)());
template<typename T> double is_class_helper(...);
}
public:
enum { value = sizeof(char) == sizeof(dont_use::is_class_helper<T>(0)) };
};
+
+
+/// isPodLike - This is a type trait that is used to determine whether a given
+/// 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;
+};
+
+
+template <class T, T v>
+struct integral_constant {
+ typedef T value_type;
+ static const value_type value = v;
+ typedef integral_constant<T,v> type;
+ operator value_type() { return value; }
+};
+
+typedef integral_constant<bool, true> true_type;
+typedef integral_constant<bool, false> false_type;
+
+/// \brief Metafunction that determines whether the two given types are
+/// equivalent.
+template<typename T, typename U> struct is_same : public false_type {};
+template<typename T> struct is_same<T, T> : public true_type {};
+
+/// \brief Metafunction that removes const qualification from a type.
+template <typename T> struct remove_const { typedef T type; };
+template <typename T> struct remove_const<const T> { typedef T type; };
+
+/// \brief Metafunction that removes volatile qualification from a type.
+template <typename T> struct remove_volatile { typedef T type; };
+template <typename T> struct remove_volatile<volatile T> { typedef T type; };
+
+/// \brief Metafunction that removes both const and volatile qualification from
+/// a type.
+template <typename T> struct remove_cv {
+ typedef typename remove_const<typename remove_volatile<T>::type>::type type;
+};
+
+/// \brief Helper to implement is_integral metafunction.
+template <typename T> struct is_integral_impl : false_type {};
+template <> struct is_integral_impl< bool> : true_type {};
+template <> struct is_integral_impl< char> : true_type {};
+template <> struct is_integral_impl< signed char> : true_type {};
+template <> struct is_integral_impl<unsigned char> : true_type {};
+template <> struct is_integral_impl< wchar_t> : true_type {};
+template <> struct is_integral_impl< short> : true_type {};
+template <> struct is_integral_impl<unsigned short> : true_type {};
+template <> struct is_integral_impl< int> : true_type {};
+template <> struct is_integral_impl<unsigned int> : true_type {};
+template <> struct is_integral_impl< long> : true_type {};
+template <> struct is_integral_impl<unsigned long> : true_type {};
+template <> struct is_integral_impl< long long> : true_type {};
+template <> struct is_integral_impl<unsigned long long> : true_type {};
+
+/// \brief Metafunction that determines whether the given type is an integral
+/// type.
+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 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(...);
+
+ typedef typename remove_reference<T>::type UnderlyingT;
+ static UnderlyingT &nonce_instance;
+
+public:
+ enum {
+ 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)))
+ };
+};
+
+// enable_if_c - Enable/disable a template based on a metafunction
+template<bool Cond, typename T = void>
+struct enable_if_c {
+ typedef T type;
+};
+
+template<typename T> struct enable_if_c<false, T> { };
+
+// enable_if - Enable/disable a template based on a metafunction
+template<typename Cond, typename T = void>
+struct enable_if : public enable_if_c<Cond::value, T> { };
+
+namespace dont_use {
+ template<typename Base> char base_of_helper(const volatile Base*);
+ template<typename Base> double base_of_helper(...);
+}
+
+/// is_base_of - Metafunction to determine whether one type is a base class of
+/// (or identical to) another type.
+template<typename Base, typename Derived>
+struct is_base_of {
+ static const bool value
+ = is_class<Base>::value && is_class<Derived>::value &&
+ sizeof(char) == sizeof(dont_use::base_of_helper<Base>((Derived*)0));
+};
+
+// remove_pointer - Metafunction to turn Foo* into Foo. Defined in
+// C++0x [meta.trans.ptr].
+template <typename T> struct remove_pointer { typedef T type; };
+template <typename T> struct remove_pointer<T*> { typedef T type; };
+template <typename T> struct remove_pointer<T*const> { typedef T type; };
+template <typename T> struct remove_pointer<T*volatile> { typedef T type; };
+template <typename T> struct remove_pointer<T*const volatile> {
+ typedef T type; };
+
+template <bool, typename T, typename F>
+struct conditional { typedef T type; };
+
+template <typename T, typename F>
+struct conditional<false, T, F> { typedef F type; };
}
+#ifdef LLVM_DEFINED_HAS_FEATURE
+#undef __has_feature
+#endif
+
#endif
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