path: root/shared/loki/ScopeGuard.h

////////////////////////////////////////////////////////////////////////////////
// The Loki Library
// Copyright (c) 2000 Andrei Alexandrescu
// Copyright (c) 2000 Petru Marginean
// Copyright (c) 2005 Joshua Lehrer
//
// Permission to use, copy, modify, distribute and sell this software for any
//     purpose is hereby granted without fee, provided that the above copyright
//     notice appear in all copies and that both that copyright notice and this
//     permission notice appear in supporting documentation.
// The author makes no representations about the
//     suitability of this software for any purpose. It is provided "as is"
//     without express or implied warranty.
////////////////////////////////////////////////////////////////////////////////
#ifndef LOKI_SCOPEGUARD_INC_
#define LOKI_SCOPEGUARD_INC_

// $Id: ScopeGuard.h 799 2006-12-20 00:37:13Z rich_sposato $


#include "RefToValue.h"

/// \defgroup ExceptionGroup Exception-safe code

namespace Loki
{

////////////////////////////////////////////////////////////////
///
/// \class ScopeGuardImplBase
/// \ingroup ExceptionGroup
///
/// Base class used by all ScopeGuard implementations.  All commonly used
/// functions are in this class (e.g. - Dismiss and SafeExecute).
///
/// See Andrei's and Petru Marginean's CUJ article
/// http://www.cuj.com/documents/s=8000/cujcexp1812alexandr/alexandr.htm
///
/// Changes to the original code by Joshua Lehrer:
/// http://www.lehrerfamily.com/scopeguard.html
////////////////////////////////////////////////////////////////

class ScopeGuardImplBase
{
    /// Copy-assignment operator is not implemented and private.
    ScopeGuardImplBase& operator =(const ScopeGuardImplBase&);

protected:

    ~ScopeGuardImplBase()
    {}

    /// Copy-constructor takes over responsibility from other ScopeGuard.
    ScopeGuardImplBase(const ScopeGuardImplBase& other) throw()
        : dismissed_(other.dismissed_)
    {
        other.Dismiss();
    }

    template <typename J>
    static void SafeExecute(J& j) throw()
    {
        if (!j.dismissed_)
            try
            {
                j.Execute();
            }
            catch(...)
            {}
    }

    mutable bool dismissed_;

public:
    ScopeGuardImplBase() throw() : dismissed_(false)
    {}

    void Dismiss() const throw()
    {
        dismissed_ = true;
    }
};

////////////////////////////////////////////////////////////////
///
/// \typedef typedef const ScopeGuardImplBase& ScopeGuard
/// \ingroup ExceptionGroup
///
////////////////////////////////////////////////////////////////

typedef const ScopeGuardImplBase& ScopeGuard;

////////////////////////////////////////////////////////////////
///
/// \class ScopeGuardImpl0
/// \ingroup ExceptionGroup
///
/// Implementation class for a standalone function or class static function
/// with no parameters.  ScopeGuard ignores any value returned from the
/// call within the Execute function.
///
/// This class has a single standalone helper function, MakeGuard which
/// creates and returns a ScopeGuard.
///
////////////////////////////////////////////////////////////////

template <typename F>
class ScopeGuardImpl0 : public ScopeGuardImplBase
{
public:
    static ScopeGuardImpl0<F> MakeGuard(F fun)
    {
        return ScopeGuardImpl0<F>(fun);
    }

    ~ScopeGuardImpl0() throw()
    {
        SafeExecute(*this);
    }

    void Execute()
    {
        fun_();
    }

protected:
    ScopeGuardImpl0(F fun) : fun_(fun)
    {}

    F fun_;
};

template <typename F>
inline ScopeGuardImpl0<F> MakeGuard(F fun)
{
    return ScopeGuardImpl0<F>::MakeGuard(fun);
}

////////////////////////////////////////////////////////////////
///
/// \class ScopeGuardImpl1
/// \ingroup ExceptionGroup
///
/// Implementation class for a standalone function or class static function
/// with one parameter.  Each parameter is copied by value - use
/// ::Loki::ByRef if you must use a reference instead.  ScopeGuard ignores
/// any value returned from the call within the Execute function.
///
/// This class has a single standalone helper function, MakeGuard which
/// creates and returns a ScopeGuard.
///
////////////////////////////////////////////////////////////////

template <typename F, typename P1>
class ScopeGuardImpl1 : public ScopeGuardImplBase
{
public:
    static ScopeGuardImpl1<F, P1> MakeGuard(F fun, P1 p1)
    {
        return ScopeGuardImpl1<F, P1>(fun, p1);
    }

    ~ScopeGuardImpl1() throw()
    {
        SafeExecute(*this);
    }

    void Execute()
    {
        fun_(p1_);
    }

protected:
    ScopeGuardImpl1(F fun, P1 p1) : fun_(fun), p1_(p1)
    {}

    F fun_;
    const P1 p1_;
};

template <typename F, typename P1>
inline ScopeGuardImpl1<F, P1> MakeGuard(F fun, P1 p1)
{
    return ScopeGuardImpl1<F, P1>::MakeGuard(fun, p1);
}

////////////////////////////////////////////////////////////////
///
/// \class ScopeGuardImpl2
/// \ingroup ExceptionGroup
///
/// Implementation class for a standalone function or class static function
/// with two parameters.  Each parameter is copied by value - use
/// ::Loki::ByRef if you must use a reference instead.  ScopeGuard ignores
/// any value returned from the call within the Execute function.
///
/// This class has a single standalone helper function, MakeGuard which
/// creates and returns a ScopeGuard.
///
////////////////////////////////////////////////////////////////

template <typename F, typename P1, typename P2>
class ScopeGuardImpl2: public ScopeGuardImplBase
{
public:
    static ScopeGuardImpl2<F, P1, P2> MakeGuard(F fun, P1 p1, P2 p2)
    {
        return ScopeGuardImpl2<F, P1, P2>(fun, p1, p2);
    }

    ~ScopeGuardImpl2() throw()
    {
        SafeExecute(*this);
    }

    void Execute()
    {
        fun_(p1_, p2_);
    }

protected:
    ScopeGuardImpl2(F fun, P1 p1, P2 p2) : fun_(fun), p1_(p1), p2_(p2)
    {}

    F fun_;
    const P1 p1_;
    const P2 p2_;
};

template <typename F, typename P1, typename P2>
inline ScopeGuardImpl2<F, P1, P2> MakeGuard(F fun, P1 p1, P2 p2)
{
    return ScopeGuardImpl2<F, P1, P2>::MakeGuard(fun, p1, p2);
}

////////////////////////////////////////////////////////////////
///
/// \class ScopeGuardImpl3
/// \ingroup ExceptionGroup
///
/// Implementation class for a standalone function or class static function
/// with three parameters.  Each parameter is copied by value - use
/// ::Loki::ByRef if you must use a reference instead.  ScopeGuard ignores
/// any value returned from the call within the Execute function.
///
/// This class has a single standalone helper function, MakeGuard which
/// creates and returns a ScopeGuard.
///
////////////////////////////////////////////////////////////////

template <typename F, typename P1, typename P2, typename P3>
class ScopeGuardImpl3 : public ScopeGuardImplBase
{
public:
    static ScopeGuardImpl3<F, P1, P2, P3> MakeGuard(F fun, P1 p1, P2 p2, P3 p3)
    {
        return ScopeGuardImpl3<F, P1, P2, P3>(fun, p1, p2, p3);
    }

    ~ScopeGuardImpl3() throw()
    {
        SafeExecute(*this);
    }

    void Execute()
    {
        fun_(p1_, p2_, p3_);
    }

protected:
    ScopeGuardImpl3(F fun, P1 p1, P2 p2, P3 p3) : fun_(fun), p1_(p1), p2_(p2), p3_(p3)
    {}

    F fun_;
    const P1 p1_;
    const P2 p2_;
    const P3 p3_;
};

template <typename F, typename P1, typename P2, typename P3>
inline ScopeGuardImpl3<F, P1, P2, P3> MakeGuard(F fun, P1 p1, P2 p2, P3 p3)
{
    return ScopeGuardImpl3<F, P1, P2, P3>::MakeGuard(fun, p1, p2, p3);
}

////////////////////////////////////////////////////////////////
///
/// \class ScopeGuardImpl4
/// \ingroup ExceptionGroup
///
/// Implementation class for a standalone function or class static function
/// with four parameters.  Each parameter is copied by value - use
/// ::Loki::ByRef if you must use a reference instead.  ScopeGuard ignores
/// any value returned from the call within the Execute function.
///
/// This class has a single standalone helper function, MakeGuard which
/// creates and returns a ScopeGuard.
///
////////////////////////////////////////////////////////////////

template < typename F, typename P1, typename P2, typename P3, typename P4 >
class ScopeGuardImpl4 : public ScopeGuardImplBase
{
public:
    static ScopeGuardImpl4< F, P1, P2, P3, P4 > MakeGuard(
        F fun, P1 p1, P2 p2, P3 p3, P4 p4 )
    {
        return ScopeGuardImpl4< F, P1, P2, P3, P4 >( fun, p1, p2, p3, p4 );
    }

    ~ScopeGuardImpl4() throw()
    {
        SafeExecute( *this );
    }

    void Execute()
    {
        fun_( p1_, p2_, p3_, p4_ );
    }

protected:
    ScopeGuardImpl4( F fun, P1 p1, P2 p2, P3 p3, P4 p4 ) :
        fun_( fun ), p1_( p1 ), p2_( p2 ), p3_( p3 ), p4_( p4 )
    {}

    F fun_;
    const P1 p1_;
    const P2 p2_;
    const P3 p3_;
    const P4 p4_;
};

template < typename F, typename P1, typename P2, typename P3, typename P4 >
inline ScopeGuardImpl4< F, P1, P2, P3, P4 > MakeGuard( F fun, P1 p1, P2 p2, P3 p3, P4 p4 )
{
    return ScopeGuardImpl4< F, P1, P2, P3, P4 >::MakeGuard( fun, p1, p2, p3, p4 );
}

////////////////////////////////////////////////////////////////
///
/// \class ScopeGuardImpl5
/// \ingroup ExceptionGroup
///
/// Implementation class for a standalone function or class static function
/// with five parameters.  Each parameter is copied by value - use
/// ::Loki::ByRef if you must use a reference instead.  ScopeGuard ignores
/// any value returned from the call within the Execute function.
///
/// This class has a single standalone helper function, MakeGuard which
/// creates and returns a ScopeGuard.
///
////////////////////////////////////////////////////////////////

template < typename F, typename P1, typename P2, typename P3, typename P4, typename P5 >
class ScopeGuardImpl5 : public ScopeGuardImplBase
{
public:
    static ScopeGuardImpl5< F, P1, P2, P3, P4, P5 > MakeGuard(
        F fun, P1 p1, P2 p2, P3 p3, P4 p4, P5 p5 )
    {
        return ScopeGuardImpl5< F, P1, P2, P3, P4, P5 >( fun, p1, p2, p3, p4, p5 );
    }

    ~ScopeGuardImpl5() throw()
    {
        SafeExecute( *this );
    }

    void Execute()
    {
        fun_( p1_, p2_, p3_, p4_, p5_ );
    }

protected:
    ScopeGuardImpl5( F fun, P1 p1, P2 p2, P3 p3, P4 p4, P5 p5 ) :
        fun_( fun ), p1_( p1 ), p2_( p2 ), p3_( p3 ), p4_( p4 ), p5_( p5 )
    {}

    F fun_;
    const P1 p1_;
    const P2 p2_;
    const P3 p3_;
    const P4 p4_;
    const P5 p5_;
};

template < typename F, typename P1, typename P2, typename P3, typename P4, typename P5 >
inline ScopeGuardImpl5< F, P1, P2, P3, P4, P5 > MakeGuard( F fun, P1 p1, P2 p2, P3 p3, P4 p4, P5 p5 )
{
    return ScopeGuardImpl5< F, P1, P2, P3, P4, P5 >::MakeGuard( fun, p1, p2, p3, p4, p5 );
}

////////////////////////////////////////////////////////////////
///
/// \class ObjScopeGuardImpl0
/// \ingroup ExceptionGroup
///
/// Implementation class for a class per-instance member function with no
/// parameters.  ScopeGuard ignores any value returned from the call within
/// the Execute function.
///
/// This class has 3 standalone helper functions which create a ScopeGuard.
/// One is MakeObjGuard, which is deprecated but provided for older code.
/// The other two are MakeGuard overloads, one which takes a pointer to an
/// object, and the other which takes a reference.
///
////////////////////////////////////////////////////////////////

template <class Obj, typename MemFun>
class ObjScopeGuardImpl0 : public ScopeGuardImplBase
{
public:
    static ObjScopeGuardImpl0<Obj, MemFun> MakeObjGuard(Obj& obj, MemFun memFun)
    {
        return ObjScopeGuardImpl0<Obj, MemFun>(obj, memFun);
    }

    ~ObjScopeGuardImpl0() throw()
    {
        SafeExecute(*this);
    }

    void Execute()
    {
        (obj_.*memFun_)();
    }

protected:
    ObjScopeGuardImpl0(Obj& obj, MemFun memFun) : obj_(obj), memFun_(memFun)
    {}

    Obj& obj_;
    MemFun memFun_;
};

template <class Obj, typename MemFun>
inline ObjScopeGuardImpl0<Obj, MemFun> MakeObjGuard(Obj& obj, MemFun memFun)
{
    return ObjScopeGuardImpl0<Obj, MemFun>::MakeObjGuard(obj, memFun);
}

template <typename Ret, class Obj1, class Obj2>
inline ObjScopeGuardImpl0<Obj1,Ret(Obj2::*)()> MakeGuard(Ret(Obj2::*memFun)(), Obj1& obj)
{
    return ObjScopeGuardImpl0<Obj1,Ret(Obj2::*)()>::MakeObjGuard(obj,memFun);
}

template <typename Ret, class Obj1, class Obj2>
inline ObjScopeGuardImpl0<Obj1,Ret(Obj2::*)()> MakeGuard(Ret(Obj2::*memFun)(), Obj1* obj)
{
    return ObjScopeGuardImpl0<Obj1,Ret(Obj2::*)()>::MakeObjGuard(*obj,memFun);
}

////////////////////////////////////////////////////////////////
///
/// \class ObjScopeGuardImpl1
/// \ingroup ExceptionGroup
///
/// Implementation class for a class per-instance member function with one
/// parameter.  The parameter is copied by value - use ::Loki::ByRef if you
/// must use a reference instead.  ScopeGuard ignores any value returned
/// from the call within the Execute function.
///
/// This class has 3 standalone helper functions which create a ScopeGuard.
/// One is MakeObjGuard, which is deprecated but provided for older code.
/// The other two are MakeGuard overloads, one which takes a pointer to an
/// object, and the other which takes a reference.
///
////////////////////////////////////////////////////////////////

template <class Obj, typename MemFun, typename P1>
class ObjScopeGuardImpl1 : public ScopeGuardImplBase
{
public:
    static ObjScopeGuardImpl1<Obj, MemFun, P1> MakeObjGuard(Obj& obj, MemFun memFun, P1 p1)
    {
        return ObjScopeGuardImpl1<Obj, MemFun, P1>(obj, memFun, p1);
    }

    ~ObjScopeGuardImpl1() throw()
    {
        SafeExecute(*this);
    }

    void Execute()
    {
        (obj_.*memFun_)(p1_);
    }

protected:
    ObjScopeGuardImpl1(Obj& obj, MemFun memFun, P1 p1) : obj_(obj), memFun_(memFun), p1_(p1)
    {}

    Obj& obj_;
    MemFun memFun_;
    const P1 p1_;
};

template <class Obj, typename MemFun, typename P1>
inline ObjScopeGuardImpl1<Obj, MemFun, P1> MakeObjGuard(Obj& obj, MemFun memFun, P1 p1)
{
    return ObjScopeGuardImpl1<Obj, MemFun, P1>::MakeObjGuard(obj, memFun, p1);
}

template <typename Ret, class Obj1, class Obj2, typename P1a, typename P1b>
inline ObjScopeGuardImpl1<Obj1,Ret(Obj2::*)(P1a),P1b> MakeGuard(Ret(Obj2::*memFun)(P1a), Obj1& obj, P1b p1)
{
    return ObjScopeGuardImpl1<Obj1,Ret(Obj2::*)(P1a),P1b>::MakeObjGuard(obj,memFun,p1);
}

template <typename Ret, class Obj1, class Obj2, typename P1a, typename P1b>
inline ObjScopeGuardImpl1<Obj1,Ret(Obj2::*)(P1a),P1b> MakeGuard(Ret(Obj2::*memFun)(P1a), Obj1* obj, P1b p1)
{
    return ObjScopeGuardImpl1<Obj1,Ret(Obj2::*)(P1a),P1b>::MakeObjGuard(*obj,memFun,p1);
}

////////////////////////////////////////////////////////////////
///
/// \class ObjScopeGuardImpl2
/// \ingroup ExceptionGroup
///
/// Implementation class for a class per-instance member function with two
/// parameters.  Each parameter is copied by value - use ::Loki::ByRef if you
/// must use a reference instead.  ScopeGuard ignores any value returned
/// from the call within the Execute function.
///
/// This class has 3 standalone helper functions which create a ScopeGuard.
/// One is MakeObjGuard, which is deprecated but provided for older code.
/// The other two are MakeGuard overloads, one which takes a pointer to an
/// object, and the other which takes a reference.
///
////////////////////////////////////////////////////////////////

template <class Obj, typename MemFun, typename P1, typename P2>
class ObjScopeGuardImpl2 : public ScopeGuardImplBase
{
public:
    static ObjScopeGuardImpl2<Obj, MemFun, P1, P2> MakeObjGuard(Obj& obj, MemFun memFun, P1 p1, P2 p2)
    {
        return ObjScopeGuardImpl2<Obj, MemFun, P1, P2>(obj, memFun, p1, p2);
    }

    ~ObjScopeGuardImpl2() throw()
    {
        SafeExecute(*this);
    }

    void Execute()
    {
        (obj_.*memFun_)(p1_, p2_);
    }

protected:
    ObjScopeGuardImpl2(Obj& obj, MemFun memFun, P1 p1, P2 p2) : obj_(obj), memFun_(memFun), p1_(p1), p2_(p2)
    {}

    Obj& obj_;
    MemFun memFun_;
    const P1 p1_;
    const P2 p2_;
};

template <class Obj, typename MemFun, typename P1, typename P2>
inline ObjScopeGuardImpl2<Obj, MemFun, P1, P2> MakeObjGuard(Obj& obj, MemFun memFun, P1 p1, P2 p2)
{
    return ObjScopeGuardImpl2<Obj, MemFun, P1, P2>::MakeObjGuard(obj, memFun, p1, p2);
}

template <typename Ret, class Obj1, class Obj2, typename P1a, typename P1b, typename P2a, typename P2b>
inline ObjScopeGuardImpl2<Obj1,Ret(Obj2::*)(P1a,P2a),P1b,P2b> MakeGuard(Ret(Obj2::*memFun)(P1a,P2a), Obj1& obj, P1b p1, P2b p2)
{
    return ObjScopeGuardImpl2<Obj1,Ret(Obj2::*)(P1a,P2a),P1b,P2b>::MakeObjGuard(obj,memFun,p1,p2);
}

template <typename Ret, class Obj1, class Obj2, typename P1a, typename P1b, typename P2a, typename P2b>
inline ObjScopeGuardImpl2<Obj1,Ret(Obj2::*)(P1a,P2a),P1b,P2b> MakeGuard(Ret(Obj2::*memFun)(P1a,P2a), Obj1* obj, P1b p1, P2b p2)
{
    return ObjScopeGuardImpl2<Obj1,Ret(Obj2::*)(P1a,P2a),P1b,P2b>::MakeObjGuard(*obj,memFun,p1,p2);
}

////////////////////////////////////////////////////////////////
///
/// \class ObjScopeGuardImpl3
/// \ingroup ExceptionGroup
///
/// Implementation class for a class per-instance member function with three
/// parameters.  Each parameter is copied by value - use ::Loki::ByRef if you
/// must use a reference instead.  ScopeGuard ignores any value returned
/// from the call within the Execute function.
///
/// This class has 3 standalone helper functions which create a ScopeGuard.
/// One is MakeObjGuard, which is deprecated but provided for older code.
/// The other two are MakeGuard overloads, one which takes a pointer to an
/// object, and the other which takes a reference.
///
////////////////////////////////////////////////////////////////

template < class Obj, typename MemFun, typename P1, typename P2, typename P3 >
class ObjScopeGuardImpl3 : public ScopeGuardImplBase
{
public:
    static ObjScopeGuardImpl3< Obj, MemFun, P1, P2, P3 > MakeObjGuard(
        Obj& obj, MemFun memFun, P1 p1, P2 p2, P3 p3 )
    {
        return ObjScopeGuardImpl3< Obj, MemFun, P1, P2, P3 >( obj, memFun, p1, p2, p3 );
    }

    ~ObjScopeGuardImpl3() throw()
    {
        SafeExecute( *this );
    }

    void Execute()
    {
        ( obj_.*memFun_ )( p1_, p2_, p3_ );
    }

protected:
    ObjScopeGuardImpl3( Obj& obj, MemFun memFun, P1 p1, P2 p2, P3 p3 ) :
        obj_( obj ), memFun_( memFun ), p1_( p1 ), p2_( p2 ), p3_( p3 )
    {}

    Obj& obj_;
    MemFun memFun_;
    const P1 p1_;
    const P2 p2_;
    const P3 p3_;
};

template < class Obj, typename MemFun, typename P1, typename P2, typename P3 >
inline ObjScopeGuardImpl3< Obj, MemFun, P1, P2, P3 > MakeObjGuard(
    Obj& obj, MemFun memFun, P1 p1, P2 p2, P3 p3 )
{
    return ObjScopeGuardImpl3< Obj, MemFun, P1, P2, P3 >::MakeObjGuard(
               obj, memFun, p1, p2, p3 );
}

template < typename Ret, class Obj1, class Obj2, typename P1a, typename P1b,
         typename P2a, typename P2b, typename P3a, typename P3b >
inline ObjScopeGuardImpl3< Obj1, Ret( Obj2::* )( P1a, P2a, P3a ), P1b, P2b, P3b >
MakeGuard( Ret( Obj2::*memFun )( P1a, P2a, P3a ), Obj1& obj, P1b p1, P2b p2, P3b p3 )
{
    return ObjScopeGuardImpl3< Obj1, Ret( Obj2::* )( P1a, P2a, P3a ), P1b, P2b, P3b >
           ::MakeObjGuard( obj, memFun, p1, p2, p3 );
}

template < typename Ret, class Obj1, class Obj2, typename P1a, typename P1b,
         typename P2a, typename P2b, typename P3a, typename P3b >
inline ObjScopeGuardImpl3< Obj1, Ret( Obj2::* )( P1a, P2a, P3a ), P1b, P2b, P3b >
MakeGuard( Ret( Obj2::*memFun )( P1a, P2a, P3a ), Obj1* obj, P1b p1, P2b p2, P3b p3 )
{
    return ObjScopeGuardImpl3< Obj1, Ret( Obj2::* )( P1a, P2a, P3a ), P1b, P2b, P3b >
           ::MakeObjGuard( *obj, memFun, p1, p2, p3 );
}

} // namespace Loki

#define LOKI_CONCATENATE_DIRECT(s1, s2)  s1##s2
#define LOKI_CONCATENATE(s1, s2)         LOKI_CONCATENATE_DIRECT(s1, s2)
#define LOKI_ANONYMOUS_VARIABLE(str)     LOKI_CONCATENATE(str, __LINE__)

#define LOKI_ON_BLOCK_EXIT      ::Loki::ScopeGuard LOKI_ANONYMOUS_VARIABLE(scopeGuard) = ::Loki::MakeGuard
#define LOKI_ON_BLOCK_EXIT_OBJ  ::Loki::ScopeGuard LOKI_ANONYMOUS_VARIABLE(scopeGuard) = ::Loki::MakeObjGuard

#endif // end file guardian