Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
       2             : /*
       3             :  * This file is part of the LibreOffice project.
       4             :  *
       5             :  * This Source Code Form is subject to the terms of the Mozilla Public
       6             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       7             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
       8             :  */
       9             : 
      10             : namespace detail
      11             : {
      12             : 
      13             : template<typename T>
      14             : struct has_clone
      15             : {
      16             :     template<typename U, U x>
      17             :     struct test;
      18             : 
      19             :     typedef char yes;
      20             :     typedef struct { char a[2]; } no;
      21             : 
      22             :     template<typename U>
      23             :     static yes& check_sig(U*, test<U* (U::*)() const, &U::clone>* = 0);
      24             :     template<typename U>
      25             :     static no& check_sig(...);
      26             : 
      27             :     enum
      28             :     {
      29             :         value = sizeof(check_sig<T>(0)) == sizeof(yes)
      30             :     };
      31             : };
      32             : 
      33             : template<typename T, bool HasClone>
      34             : struct cloner
      35             : {
      36           0 :     static T* clone(T* const other)
      37             :     {
      38           0 :         return new T(*other);
      39             :     }
      40             : };
      41             : 
      42             : template<typename T>
      43             : struct cloner<T, true>
      44             : {
      45           0 :     static T* clone(T* const other)
      46             :     {
      47           0 :         return other->clone();
      48             :     }
      49             : };
      50             : 
      51             : }
      52             : 
      53             : /** Creates a new copy of the passed object.
      54             :     If other is 0, just returns 0. Otherwise, if other has function
      55             :     named clone with signature T* (T::*)() const, the function is called.
      56             :     Otherwise, copy constructor is used.
      57             : 
      58             :     @returns 0 or newly allocated object
      59             :  */
      60             : template<typename T>
      61           0 : T* clone(T* const other)
      62             : {
      63           0 :     return other ? ::detail::cloner<T, ::detail::has_clone<T>::value>::clone(other) : 0;
      64             : }
      65             : 
      66             : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */