// Copyright (c) 2009 libmv authors.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.

#ifndef LIBMV_BASE_SCOPED_PTR_H
#define LIBMV_BASE_SCOPED_PTR_H

#include <cassert>
#include <cstddef>

namespace libmv {

/**
 * A handle for a heap-allocated resource that should be freed when it goes out
 * of scope. This looks similar to the one found in TR1.
 */
template <typename T>
class scoped_ptr {
 public:
  scoped_ptr(T* resource) : resource_(resource) {}
  ~scoped_ptr() { reset(0); }

  T* get() const { return resource_; }
  T* operator->() const { return resource_; }
  T& operator*() const { return *resource_; }

  void reset(T* new_resource) {
    if (sizeof(T)) {
      delete resource_;
    }
    resource_ = new_resource;
  }

  T* release() {
    T* released_resource = resource_;
    resource_ = 0;
    return released_resource;
  }

 private:
  // No copying allowed.
  T* resource_;
};

// Same as scoped_ptr but caller must allocate the data
// with new[] and the destructor will free the memory
// using delete[].
template <typename T>
class scoped_array {
 public:
  scoped_array(T* array) : array_(array) {}
  ~scoped_array() { reset(NULL); }

  T* get() const { return array_; }

  T& operator[](std::ptrdiff_t i) const {
    assert(i >= 0);
    assert(array_ != NULL);
    return array_[i];
  }

  void reset(T* new_array) {
    if (sizeof(T)) {
      delete[] array_;
    }
    array_ = new_array;
  }

  T* release() {
    T* released_array = array_;
    array_ = NULL;
    return released_array;
  }

 private:
  T* array_;

  // Forbid comparison of different scoped_array types.
  template <typename T2>
  bool operator==(scoped_array<T2> const& p2) const;
  template <typename T2>
  bool operator!=(scoped_array<T2> const& p2) const;

  // Disallow evil constructors
  scoped_array(const scoped_array&);
  void operator=(const scoped_array&);
};

}  // namespace libmv

#endif  // LIBMV_BASE_SCOPED_PTR_H
