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llvm-6502/include/llvm/ADT/NullablePtr.h
Chris Lattner 1ec9e6a5dc add a new NullablePtr class which makes it more obvious in API
that a pointer can be null, forcing clients to think about it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109348 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-24 18:47:46 +00:00

53 lines
1.5 KiB
C++

//===- llvm/ADT/NullablePtr.h - A pointer that allows null ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines and implements the NullablePtr class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_NULLABLE_PTR_H
#define LLVM_ADT_NULLABLE_PTR_H
#include <cassert>
#include <cstddef>
namespace llvm {
/// NullablePtr pointer wrapper - NullablePtr is used for APIs where a
/// potentially-null pointer gets passed around that must be explicitly handled
/// in lots of places. By putting a wrapper around the null pointer, it makes
/// it more likely that the null pointer case will be handled correctly.
template<class T>
class NullablePtr {
T *Ptr;
public:
NullablePtr(T *P = 0) : Ptr(P) {}
bool isNull() const { return Ptr == 0; }
bool isNonNull() const { return Ptr != 0; }
/// get - Return the pointer if it is non-null.
const T *get() const {
assert(Ptr && "Pointer wasn't checked for null!");
return Ptr;
}
/// get - Return the pointer if it is non-null.
T *get() {
assert(Ptr && "Pointer wasn't checked for null!");
return Ptr;
}
T *getPtrOrNull() { return Ptr; }
const T *getPtrOrNull() const { return Ptr; }
};
} // end namespace llvm
#endif