safe_bool.h

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
 *  Copyright (C) 2004-2011 the Initial Developer.
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 */
 
 
 
/** @class lass::num::SafeBool
 *  @brief a boolean that can only be used in boolean context
 *  @author Bram de Greve [BdG]
 */
 
#ifndef LASS_GUARDIAN_OF_INCLUSION_NUM_SAFE_BOOL_H
#define LASS_GUARDIAN_OF_INCLUSION_NUM_SAFE_BOOL_H
 
#include "num_common.h"
 
namespace lass
{
namespace num
{
 
namespace impl
{
    struct Dummy
    {
        void method() {}
    };
}
 
LASS_DEPRECATED("use explicit operator bool() instead") typedef void (impl::Dummy::* SafeBool)();
 
#if LASS_COMPILER_TYPE == LASS_COMPILER_TYPE_MSVC
#   pragma warning(push)
#   pragma warning(disable: 4996) // 'deprecated-declaration': deprecation-message (or "was declared deprecated")
#else
#   pragma GCC diagnostic push
#   pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#endif
 
LASS_DEPRECATED("use explicit operator bool() instead") const SafeBool safeTrue = &impl::Dummy::method;
LASS_DEPRECATED("use explicit operator bool() instead") const SafeBool safeFalse = 0;
 
LASS_DEPRECATED("use explicit operator bool() instead") inline SafeBool safeBool(bool x) { return x ? safeTrue : safeFalse; }
 
#if LASS_COMPILER_TYPE == LASS_COMPILER_TYPE_MSVC
#   pragma warning(pop)
#else
#   pragma GCC diagnostic pop
#endif
 
}
 
}
 
#endif
 
// EOF