MC: Move COFF enumeration constants to llvm/Support/COFF.h, patch by Michael

[oota-llvm.git] / include / llvm / Support / type_traits.h

diff --git a/include/llvm/Support/type_traits.h b/include/llvm/Support/type_traits.h
index ce916b5fcc6d5c74ea9151b41e76c227562022fa..515295bdd66feb7e4471710ee403acac78506d9c 100644 (file)
--- a/include/llvm/Support/type_traits.h
+++ b/include/llvm/Support/type_traits.h
@@ -17,13 +17,15 @@
 #ifndef LLVM_SUPPORT_TYPE_TRAITS_H
 #define LLVM_SUPPORT_TYPE_TRAITS_H
 
+#include <utility>
+
 // 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
@@ -48,6 +50,23 @@ struct is_class
  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 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;
+};
+
+// 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;
+};
+  
 
 /// \brief Metafunction that determines whether the two given types are 
 /// equivalent.