1//===- llvm/ADT/NullablePtr.h - A pointer that allows null ------*- C++ -*-===//
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 defines and implements the NullablePtr class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_ADT_NULLABLEPTR_H
15#define LLVM_ADT_NULLABLEPTR_H
16
17#include <cassert>
18#include <cstddef>
19
20namespace llvm {
21/// NullablePtr pointer wrapper - NullablePtr is used for APIs where a
22/// potentially-null pointer gets passed around that must be explicitly handled
23/// in lots of places.  By putting a wrapper around the null pointer, it makes
24/// it more likely that the null pointer case will be handled correctly.
25template<class T>
26class NullablePtr {
27  T *Ptr;
28public:
29  NullablePtr(T *P = 0) : Ptr(P) {}
30
31  bool isNull() const { return Ptr == 0; }
32  bool isNonNull() const { return Ptr != 0; }
33
34  /// get - Return the pointer if it is non-null.
35  const T *get() const {
36    assert(Ptr && "Pointer wasn't checked for null!");
37    return Ptr;
38  }
39
40  /// get - Return the pointer if it is non-null.
41  T *get() {
42    assert(Ptr && "Pointer wasn't checked for null!");
43    return Ptr;
44  }
45
46  T *getPtrOrNull() { return Ptr; }
47  const T *getPtrOrNull() const { return Ptr; }
48};
49
50} // end namespace llvm
51
52#endif
53