src/base/cast.hh

   1 /*
   2  * Copyright (c) 2008 The Hewlett-Packard Development Company
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Nathan Binkert
  29  */
  30
  31 #ifndef __BASE_CAST_HH__
  32 #define __BASE_CAST_HH__
  33
  34 #include <cassert>
  35
  36 // This is designed for situations where we have a pointer to a base
  37 // type, but in all cases when we cast it to a derived type, we know
  38 // by construction that it should work correctly.
  39
  40 #if defined(DEBUG)
  41
  42 // In debug builds, do the dynamic cast and assert the result is good
  43
  44 template <class T, class U>
  45 inline T
  46 safe_cast(U ptr)
  47 {
  48     T ret = dynamic_cast<T>(ptr);
  49     assert(ret);
  50     return ret;
  51 }
  52
  53 #else
  54
  55 // In non debug builds statically cast the result to the pointer we
  56 // want to use.  This is technically unsafe, but this is only for
  57 // cases where we know that this should work by construction.
  58
  59 template <class T, class U>
  60 inline T
  61 safe_cast(U ptr)
  62 {
  63     return static_cast<T>(ptr);
  64 }
  65
  66 #endif
  67
  68 #endif // __BASE_CAST_HH__