// Ceres Solver - A fast non-linear least squares minimizer // Copyright 2010, 2011, 2012 Google Inc. All rights reserved. // http://code.google.com/p/ceres-solver/ // // 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. // // Author: jorg@google.com (Jorg Brown) // // This is an implementation designed to match the anticipated future TR2 // implementation of the scoped_ptr class, and its closely-related brethren, // scoped_array, scoped_ptr_malloc, and make_scoped_ptr. #ifndef CERES_PUBLIC_INTERNAL_SCOPED_PTR_H_ #define CERES_PUBLIC_INTERNAL_SCOPED_PTR_H_ #include <assert.h> #include <stdlib.h> #include <cstddef> #include <algorithm> namespace ceres { namespace internal { template <class C> class scoped_ptr; template <class C, class Free> class scoped_ptr_malloc; template <class C> class scoped_array; template <class C> scoped_ptr<C> make_scoped_ptr(C *); // A scoped_ptr<T> is like a T*, except that the destructor of // scoped_ptr<T> automatically deletes the pointer it holds (if // any). That is, scoped_ptr<T> owns the T object that it points // to. Like a T*, a scoped_ptr<T> may hold either NULL or a pointer to // a T object. Also like T*, scoped_ptr<T> is thread-compatible, and // once you dereference it, you get the threadsafety guarantees of T. // // The size of a scoped_ptr is small: sizeof(scoped_ptr<C>) == sizeof(C*) template <class C> class scoped_ptr { public: // The element type typedef C element_type; // Constructor. Defaults to intializing with NULL. // There is no way to create an uninitialized scoped_ptr. // The input parameter must be allocated with new. explicit scoped_ptr(C* p = NULL) : ptr_(p) { } // Destructor. If there is a C object, delete it. // We don't need to test ptr_ == NULL because C++ does that for us. ~scoped_ptr() { enum { type_must_be_complete = sizeof(C) }; delete ptr_; } // Reset. Deletes the current owned object, if any. // Then takes ownership of a new object, if given. // this->reset(this->get()) works. void reset(C* p = NULL) { if (p != ptr_) { enum { type_must_be_complete = sizeof(C) }; delete ptr_; ptr_ = p; } } // Accessors to get the owned object. // operator* and operator-> will assert() if there is no current object. C& operator*() const { assert(ptr_ != NULL); return *ptr_; } C* operator->() const { assert(ptr_ != NULL); return ptr_; } C* get() const { return ptr_; } // Comparison operators. // These return whether a scoped_ptr and a raw pointer refer to // the same object, not just to two different but equal objects. bool operator==(const C* p) const { return ptr_ == p; } bool operator!=(const C* p) const { return ptr_ != p; } // Swap two scoped pointers. void swap(scoped_ptr& p2) { C* tmp = ptr_; ptr_ = p2.ptr_; p2.ptr_ = tmp; } // Release a pointer. // The return value is the current pointer held by this object. // If this object holds a NULL pointer, the return value is NULL. // After this operation, this object will hold a NULL pointer, // and will not own the object any more. C* release() { C* retVal = ptr_; ptr_ = NULL; return retVal; } private: C* ptr_; // google3 friend class that can access copy ctor (although if it actually // calls a copy ctor, there will be a problem) see below friend scoped_ptr<C> make_scoped_ptr<C>(C *p); // Forbid comparison of scoped_ptr types. If C2 != C, it totally doesn't // make sense, and if C2 == C, it still doesn't make sense because you should // never have the same object owned by two different scoped_ptrs. template <class C2> bool operator==(scoped_ptr<C2> const& p2) const; template <class C2> bool operator!=(scoped_ptr<C2> const& p2) const; // Disallow evil constructors scoped_ptr(const scoped_ptr&); void operator=(const scoped_ptr&); }; // Free functions template <class C> inline void swap(scoped_ptr<C>& p1, scoped_ptr<C>& p2) { p1.swap(p2); } template <class C> inline bool operator==(const C* p1, const scoped_ptr<C>& p2) { return p1 == p2.get(); } template <class C> inline bool operator==(const C* p1, const scoped_ptr<const C>& p2) { return p1 == p2.get(); } template <class C> inline bool operator!=(const C* p1, const scoped_ptr<C>& p2) { return p1 != p2.get(); } template <class C> inline bool operator!=(const C* p1, const scoped_ptr<const C>& p2) { return p1 != p2.get(); } template <class C> scoped_ptr<C> make_scoped_ptr(C *p) { // This does nothing but to return a scoped_ptr of the type that the passed // pointer is of. (This eliminates the need to specify the name of T when // making a scoped_ptr that is used anonymously/temporarily.) From an // access control point of view, we construct an unnamed scoped_ptr here // which we return and thus copy-construct. Hence, we need to have access // to scoped_ptr::scoped_ptr(scoped_ptr const &). However, it is guaranteed // that we never actually call the copy constructor, which is a good thing // as we would call the temporary's object destructor (and thus delete p) // if we actually did copy some object, here. return scoped_ptr<C>(p); } // scoped_array<C> is like scoped_ptr<C>, except that the caller must allocate // with new [] and the destructor deletes objects with delete []. // // As with scoped_ptr<C>, a scoped_array<C> either points to an object // or is NULL. A scoped_array<C> owns the object that it points to. // scoped_array<T> is thread-compatible, and once you index into it, // the returned objects have only the threadsafety guarantees of T. // // Size: sizeof(scoped_array<C>) == sizeof(C*) template <class C> class scoped_array { public: // The element type typedef C element_type; // Constructor. Defaults to intializing with NULL. // There is no way to create an uninitialized scoped_array. // The input parameter must be allocated with new []. explicit scoped_array(C* p = NULL) : array_(p) { } // Destructor. If there is a C object, delete it. // We don't need to test ptr_ == NULL because C++ does that for us. ~scoped_array() { enum { type_must_be_complete = sizeof(C) }; delete[] array_; } // Reset. Deletes the current owned object, if any. // Then takes ownership of a new object, if given. // this->reset(this->get()) works. void reset(C* p = NULL) { if (p != array_) { enum { type_must_be_complete = sizeof(C) }; delete[] array_; array_ = p; } } // Get one element of the current object. // Will assert() if there is no current object, or index i is negative. C& operator[](std::ptrdiff_t i) const { assert(i >= 0); assert(array_ != NULL); return array_[i]; } // Get a pointer to the zeroth element of the current object. // If there is no current object, return NULL. C* get() const { return array_; } // Comparison operators. // These return whether a scoped_array and a raw pointer refer to // the same array, not just to two different but equal arrays. bool operator==(const C* p) const { return array_ == p; } bool operator!=(const C* p) const { return array_ != p; } // Swap two scoped arrays. void swap(scoped_array& p2) { C* tmp = array_; array_ = p2.array_; p2.array_ = tmp; } // Release an array. // The return value is the current pointer held by this object. // If this object holds a NULL pointer, the return value is NULL. // After this operation, this object will hold a NULL pointer, // and will not own the object any more. C* release() { C* retVal = array_; array_ = NULL; return retVal; } private: C* array_; // Forbid comparison of different scoped_array types. template <class C2> bool operator==(scoped_array<C2> const& p2) const; template <class C2> bool operator!=(scoped_array<C2> const& p2) const; // Disallow evil constructors scoped_array(const scoped_array&); void operator=(const scoped_array&); }; // Free functions template <class C> inline void swap(scoped_array<C>& p1, scoped_array<C>& p2) { p1.swap(p2); } template <class C> inline bool operator==(const C* p1, const scoped_array<C>& p2) { return p1 == p2.get(); } template <class C> inline bool operator==(const C* p1, const scoped_array<const C>& p2) { return p1 == p2.get(); } template <class C> inline bool operator!=(const C* p1, const scoped_array<C>& p2) { return p1 != p2.get(); } template <class C> inline bool operator!=(const C* p1, const scoped_array<const C>& p2) { return p1 != p2.get(); } // This class wraps the c library function free() in a class that can be // passed as a template argument to scoped_ptr_malloc below. class ScopedPtrMallocFree { public: inline void operator()(void* x) const { free(x); } }; } // namespace internal } // namespace ceres #endif // CERES_PUBLIC_INTERNAL_SCOPED_PTR_H_