Convert //third_party from scoped_ptr to std::unique_ptr

third_party/cld/base/scoped_ptr.h

-// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BASE_SCOPED_PTR_H__
-#define BASE_SCOPED_PTR_H__
-
-//  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.
-//
-//  See http://wiki/Main/ScopedPointerInterface for the spec that drove this
-//  file.
-
-#include <assert.h>
-#include <stdlib.h>
-#include <cstddef>
-
-#ifdef OS_EMBEDDED_QNX
-// NOTE(akirmse):
-// The C++ standard says that <stdlib.h> declares both ::foo and std::foo
-// But this isn't done in QNX version 6.3.2 200709062316.
-using std::free;
-using std::malloc;
-using std::realloc;
-#endif
-
-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);
-  }
-};
-
-// scoped_ptr_malloc<> is similar to scoped_ptr<>, but it accepts a
-// second template argument, the functor used to free the object.
-
-template<class C, class FreeProc = ScopedPtrMallocFree>
-class scoped_ptr_malloc {
- public:
-
-  // The element type
-  typedef C element_type;
-
-  // Construction with no arguments sets ptr_ to NULL.
-  // There is no way to create an uninitialized scoped_ptr.
-  // The input parameter must be allocated with an allocator that matches the
-  // Free functor.  For the default Free functor, this is malloc, calloc, or
-  // realloc.
-  explicit scoped_ptr_malloc(): ptr_(NULL) { }
-
-  // Construct with a C*, and provides an error with a D*.
-  template<class must_be_C>
-  explicit scoped_ptr_malloc(must_be_C* p): ptr_(p) { }
-
-  // Construct with a void*, such as you get from malloc.
-  explicit scoped_ptr_malloc(void *p): ptr_(static_cast<C*>(p)) { }
-
-  // Destructor.  If there is a C object, call the Free functor.
-  ~scoped_ptr_malloc() {
-    free_(ptr_);
-  }
-
-  // Reset.  Calls the Free functor on 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 (ptr_ != p) {
-      free_(ptr_);
-      ptr_ = p;
-    }
-  }
-
-  // Reallocates the existing pointer, and returns 'true' if
-  // the reallcation is succesfull.  If the reallocation failed, then
-  // the pointer remains in its previous state.
-  //
-  // Note: this calls realloc() directly, even if an alternate 'free'
-  // functor is provided in the template instantiation.
-  bool try_realloc(size_t new_size) {
-    C* new_ptr = static_cast<C*>(realloc(ptr_, new_size));
-    if (new_ptr == NULL) {
-      return false;
-    }
-    ptr_ = new_ptr;
-    return true;
-  }
-
-  // Get the current object.
-  // operator* and operator-> will cause an assert() failure 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_malloc and a plain pointer refer
-  // to the same object, not just to two different but equal objects.
-  // For compatibility with the boost-derived implementation, these
-  // take non-const arguments.
-  bool operator==(C* p) const {
-    return ptr_ == p;
-  }
-
-  bool operator!=(C* p) const {
-    return ptr_ != p;
-  }
-
-  // Swap two scoped pointers.
-  void swap(scoped_ptr_malloc & b) {
-    C* tmp = b.ptr_;
-    b.ptr_ = ptr_;
-    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* tmp = ptr_;
-    ptr_ = NULL;
-    return tmp;
-  }
-
- private:
-  C* ptr_;
-
-  // no reason to use these: each scoped_ptr_malloc should have its own object
-  template <class C2, class GP>
-  bool operator==(scoped_ptr_malloc<C2, GP> const& p) const;
-  template <class C2, class GP>
-  bool operator!=(scoped_ptr_malloc<C2, GP> const& p) const;
-
-  static FreeProc const free_;
-
-  // Disallow evil constructors
-  scoped_ptr_malloc(const scoped_ptr_malloc&);
-  void operator=(const scoped_ptr_malloc&);
-};
-
-template<class C, class FP>
-FP const scoped_ptr_malloc<C, FP>::free_ = FP();
-
-template<class C, class FP> inline
-void swap(scoped_ptr_malloc<C, FP>& a, scoped_ptr_malloc<C, FP>& b) {
-  a.swap(b);
-}
-
-template<class C, class FP> inline
-bool operator==(C* p, const scoped_ptr_malloc<C, FP>& b) {
-  return p == b.get();
-}
-
-template<class C, class FP> inline
-bool operator!=(C* p, const scoped_ptr_malloc<C, FP>& b) {
-  return p != b.get();
-}
-
-#endif  // BASE_SCOPED_PTR_H__