v8/src/smart-pointer.h
mikhail.naganov@gmail.com 30a0a7de43 Split nested namespaces declaration in two lines in accordance with C++ Style Guide.
This issue was raised by Brett Wilson while reviewing my changelist for readability. Craig Silverstein (one of C++ SG maintainers) confirmed that we should declare one namespace per line. Our way of namespaces closing seems not violating style guides (there is no clear agreement on it), so I left it intact.

Review URL: http://codereview.chromium.org/115756


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2038 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2009-05-25 10:05:56 +00:00

110 lines
3.6 KiB
C++

// Copyright 2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_SMART_POINTER_H_
#define V8_SMART_POINTER_H_
namespace v8 {
namespace internal {
// A 'scoped array pointer' that calls DeleteArray on its pointer when the
// destructor is called.
template<typename T>
class SmartPointer {
public:
// Default constructor. Construct an empty scoped pointer.
inline SmartPointer() : p(NULL) {}
// Construct a scoped pointer from a plain one.
explicit inline SmartPointer(T* pointer) : p(pointer) {}
// Copy constructor removes the pointer from the original to avoid double
// freeing.
inline SmartPointer(const SmartPointer<T>& rhs) : p(rhs.p) {
const_cast<SmartPointer<T>&>(rhs).p = NULL;
}
// When the destructor of the scoped pointer is executed the plain pointer
// is deleted using DeleteArray. This implies that you must allocate with
// NewArray.
inline ~SmartPointer() { if (p) DeleteArray(p); }
// You can get the underlying pointer out with the * operator.
inline T* operator*() { return p; }
// You can use [n] to index as if it was a plain pointer
inline T& operator[](size_t i) {
return p[i];
}
// We don't have implicit conversion to a T* since that hinders migration:
// You would not be able to change a method from returning a T* to
// returning an SmartPointer<T> and then get errors wherever it is used.
// If you want to take out the plain pointer and don't want it automatically
// deleted then call Detach(). Afterwards, the smart pointer is empty
// (NULL).
inline T* Detach() {
T* temp = p;
p = NULL;
return temp;
}
// Assignment requires an empty (NULL) SmartPointer as the receiver. Like
// the copy constructor it removes the pointer in the original to avoid
// double freeing.
inline SmartPointer& operator=(const SmartPointer<T>& rhs) {
ASSERT(is_empty());
T* tmp = rhs.p; // swap to handle self-assignment
const_cast<SmartPointer<T>&>(rhs).p = NULL;
p = tmp;
return *this;
}
inline bool is_empty() {
return p == NULL;
}
private:
T* p;
};
} } // namespace v8::internal
#endif // V8_SMART_POINTER_H_