TypeOrdering.h revision 06159e878569e5f39bf0e8f11b84ac3ad0970597 
1//===-------------- TypeOrdering.h - Total ordering for types -------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file provides a function objects and specializations that
11//  allow QualType values to be sorted, used in std::maps, std::sets,
12//  llvm::DenseMaps, and llvm::DenseSets.
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_CLANG_TYPE_ORDERING_H
17#define LLVM_CLANG_TYPE_ORDERING_H
18
19#include "clang/AST/Type.h"
20#include <functional>
21
22namespace clang {
23
24/// QualTypeOrdering - Function object that provides a total ordering
25/// on QualType values.
26struct QualTypeOrdering : std::binary_function<QualType, QualType, bool> {
27  bool operator()(QualType T1, QualType T2) const {
28    return std::less<void*>()(T1.getAsOpaquePtr(), T2.getAsOpaquePtr());
29  }
30};
31
32}
33
34namespace llvm {
35  template<class> struct DenseMapInfo;
36
37  template<> struct DenseMapInfo<clang::QualType> {
38    static inline clang::QualType getEmptyKey() { return clang::QualType(); }
39
40    static inline clang::QualType getTombstoneKey() {
41      using clang::QualType;
42      return QualType::getFromOpaquePtr(reinterpret_cast<clang::Type *>(-1));
43    }
44
45    static unsigned getHashValue(clang::QualType Val) {
46      return (unsigned)((uintptr_t)Val.getAsOpaquePtr()) ^
47            ((unsigned)((uintptr_t)Val.getAsOpaquePtr() >> 9));
48    }
49
50    static bool isEqual(clang::QualType LHS, clang::QualType RHS) {
51      return LHS == RHS;
52    }
53  };
54
55  // FIXME: Move to Type.h
56  template <>
57  struct isPodLike<clang::QualType> { static const bool value = true; };
58}
59
60#endif
61