safe_bool.hh

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//
// Copyright (c) 2020 Fraunhofer Institute for Applied Information Technology (FIT)
//                    Network Research Group (NET)
//                    Schloss Birlinghoven, 53754 Sankt Augustin, GERMANY
//                    Contact: support@wiback.org
//
// This file is part of the SENF code tree.
// It is licensed under the 3-clause BSD License (aka New BSD License).
// See LICENSE.txt in the top level directory for details or visit
// https://opensource.org/licenses/BSD-3-Clause
//


#ifndef HH_SENF_Utils_safe_bool_
#define HH_SENF_Utils_safe_bool_ 1

// Custom includes
#include <senf/autoconf.hh>

//#include "safe_bool.mpp"
//-/////////////////////////////////////////////////////////////////////////////////////////////////

namespace senf {

#ifdef SENF_CXX11_ENABLED

    template <typename T>
    class comparable_safe_bool
    {
    public:
        explicit operator bool() const;
    };

    template <typename T>
    class safe_bool : public comparable_safe_bool<T> {};

#else

    class safe_bool_base
    {
    protected:
        typedef void (safe_bool_base::*bool_type)() const;
        void this_type_does_not_support_comparisons() const;

        // Just here to make them protected ...

        safe_bool_base();
        safe_bool_base(const safe_bool_base&);
        safe_bool_base& operator=(const safe_bool_base&);
        ~safe_bool_base();
    };

    template <typename T>
    class comparable_safe_bool
        : public safe_bool_base
    {
    public:
        operator bool_type() const;
        bool operator !() const;

    protected:
        ~comparable_safe_bool();
    };

    template <typename T>
    class safe_bool : public comparable_safe_bool<T> {};

    template <typename T, typename U>
    void operator==(const safe_bool<T>& lhs,const safe_bool<U>& rhs);

    template <typename T,typename U>
    void operator!=(const safe_bool<T>& lhs,const safe_bool<U>& rhs);

#endif

}

//-/////////////////////////////////////////////////////////////////////////////////////////////////
#include "safe_bool.cci"
//#include "safe_bool.ct"
#include "safe_bool.cti"
//#include "safe_bool.mpp"
#endif


// Local Variables:
// mode: c++
// fill-column: 100
// c-file-style: "senf"
// indent-tabs-mode: nil
// ispell-local-dictionary: "american"
// compile-command: "scons -u test"
// comment-column: 40
// End: