/* Copyright 2003-2020 Joaquin M Lopez Munoz.

 * Distributed under the Boost Software License, Version 1.0.

 * (See accompanying file LICENSE_1_0.txt or copy at

 * http://www.boost.org/LICENSE_1_0.txt)

 *

 * See http://www.boost.org/libs/multi_index for library home page.

 */

#ifndef BOOST_MULTI_INDEX_DETAIL_SCOPE_GUARD_HPP

#define BOOST_MULTI_INDEX_DETAIL_SCOPE_GUARD_HPP

#if defined(_MSC_VER)

#pragma once

#endif

#include <boost/core/no_exceptions_support.hpp>

#include <boost/mpl/if.hpp>

namespace boost{

namespace multi_index{

namespace detail{

/* Until some official version of the ScopeGuard idiom makes it into Boost,

 * we locally define our own. This is a merely reformated version of

 * ScopeGuard.h as defined in:

 *   Alexandrescu, A., Marginean, P.:"Generic<Programming>: Change the Way You

 *     Write Exception-Safe Code - Forever", C/C++ Users Jornal, Dec 2000,

 *     http://www.drdobbs.com/184403758

 * with the following modifications:

 *   - General pretty formatting (pretty to my taste at least.)

 *   - Naming style changed to standard C++ library requirements.

 *   - Added scope_guard_impl4 and obj_scope_guard_impl3, (Boost.MultiIndex

 *     needs them). A better design would provide guards for many more

 *     arguments through the Boost Preprocessor Library.

 *   - Added scope_guard_impl_base::touch (see below.)

 *   - Removed RefHolder and ByRef, whose functionality is provided

 *     already by Boost.Ref.

 *   - Removed static make_guard's and make_obj_guard's, so that the code

 *     will work even if BOOST_NO_MEMBER_TEMPLATES is defined. This forces

 *     us to move some private ctors to public, though.

 *

 * NB: CodeWarrior Pro 8 seems to have problems looking up safe_execute

 * without an explicit qualification.

 * 

 * We also define the following variants of the idiom:

 * 

 *   - make_guard_if_c<bool>( ... )

 *   - make_guard_if<IntegralConstant>( ... )

 *   - make_obj_guard_if_c<bool>( ... )

 *   - make_obj_guard_if<IntegralConstant>( ... )

 * which may be used with a compile-time constant to yield

 * a "null_guard" if the boolean compile-time parameter is false,

 * or conversely, the guard is only constructed if the constant is true.

 * This is useful to avoid extra tagging, because the returned

 * null_guard can be optimzed comlpetely away by the compiler.

 */

class scope_guard_impl_base

{

public:

  scope_guard_impl_base():dismissed_(false){}

  void dismiss()const{dismissed_=true;}

  /* This helps prevent some "unused variable" warnings under, for instance,

   * GCC 3.2.

   */

  void touch()const{}

protected:

  ~scope_guard_impl_base(){}

  scope_guard_impl_base(const scope_guard_impl_base& other):

    dismissed_(other.dismissed_)

  {

    other.dismiss();

  }

  template<typename J>

  static void safe_execute(J& j){

    BOOST_TRY{

      if(!j.dismissed_)j.execute();

    }

    BOOST_CATCH(...){}

    BOOST_CATCH_END

  }

  mutable bool dismissed_;

private:

  scope_guard_impl_base& operator=(const scope_guard_impl_base&);

};

typedef const scope_guard_impl_base& scope_guard;

struct null_guard : public scope_guard_impl_base

{

    template< class T1 >

    null_guard( const T1& )

    { }

    template< class T1, class T2 >

    null_guard( const T1&, const T2& )

    { }

    template< class T1, class T2, class T3 >

    null_guard( const T1&, const T2&, const T3& )

    { }

    template< class T1, class T2, class T3, class T4 >

    null_guard( const T1&, const T2&, const T3&, const T4& )

    { }

    template< class T1, class T2, class T3, class T4, class T5 >

    null_guard( const T1&, const T2&, const T3&, const T4&, const T5& )

    { }

};

template< bool cond, class T >

struct null_guard_return

{

    typedef typename boost::mpl::if_c<cond,T,null_guard>::type type;

};

template<typename F>

class scope_guard_impl0:public scope_guard_impl_base

{

public:

  scope_guard_impl0(F fun):fun_(fun){}

  ~scope_guard_impl0(){scope_guard_impl_base::safe_execute(*this);}

  void execute(){fun_();}

protected:

  F fun_;

};

template<typename F> 

inline scope_guard_impl0<F> make_guard(F fun)

{

  return scope_guard_impl0<F>(fun);

}

template<bool cond, typename F> 

inline typename null_guard_return<cond,scope_guard_impl0<F> >::type  

make_guard_if_c(F fun)

{

  return typename null_guard_return<cond,scope_guard_impl0<F> >::type(fun);

}

template<typename C, typename F> 

inline typename null_guard_return<C::value,scope_guard_impl0<F> >::type  

make_guard_if(F fun)

{

  return make_guard_if<C::value>(fun);

}

template<typename F,typename P1>

class scope_guard_impl1:public scope_guard_impl_base

{

public:

  scope_guard_impl1(F fun,P1 p1):fun_(fun),p1_(p1){}

  ~scope_guard_impl1(){scope_guard_impl_base::safe_execute(*this);}

  void execute(){fun_(p1_);}

protected:

  F        fun_;

  const P1 p1_;

};

template<typename F,typename P1> 

inline scope_guard_impl1<F,P1> make_guard(F fun,P1 p1)

{

  return scope_guard_impl1<F,P1>(fun,p1);

}

template<bool cond, typename F,typename P1> 

inline typename null_guard_return<cond,scope_guard_impl1<F,P1> >::type 

make_guard_if_c(F fun,P1 p1)

{

  return typename null_guard_return<cond,scope_guard_impl1<F,P1> >::type(fun,p1);

}

template<typename C, typename F,typename P1> 

inline typename null_guard_return<C::value,scope_guard_impl1<F,P1> >::type 

make_guard_if(F fun,P1 p1)

{

  return make_guard_if_c<C::value>(fun,p1);

}

template<typename F,typename P1,typename P2>

class scope_guard_impl2:public scope_guard_impl_base

{

public:

  scope_guard_impl2(F fun,P1 p1,P2 p2):fun_(fun),p1_(p1),p2_(p2){}

  ~scope_guard_impl2(){scope_guard_impl_base::safe_execute(*this);}

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

protected:

  F        fun_;

  const P1 p1_;

  const P2 p2_;

};

template<typename F,typename P1,typename P2>

inline scope_guard_impl2<F,P1,P2> make_guard(F fun,P1 p1,P2 p2)

{

  return scope_guard_impl2<F,P1,P2>(fun,p1,p2);

}

template<bool cond, typename F,typename P1,typename P2>

inline typename null_guard_return<cond,scope_guard_impl2<F,P1,P2> >::type

make_guard_if_c(F fun,P1 p1,P2 p2)

{

  return typename null_guard_return<cond,scope_guard_impl2<F,P1,P2> >::type(fun,p1,p2);

}

template<typename C, typename F,typename P1,typename P2>

inline typename null_guard_return<C::value,scope_guard_impl2<F,P1,P2> >::type

make_guard_if(F fun,P1 p1,P2 p2)

{

  return make_guard_if_c<C::value>(fun,p1,p2);

}

template<typename F,typename P1,typename P2,typename P3>

class scope_guard_impl3:public scope_guard_impl_base

{

public:

  scope_guard_impl3(F fun,P1 p1,P2 p2,P3 p3):fun_(fun),p1_(p1),p2_(p2),p3_(p3){}

  ~scope_guard_impl3(){scope_guard_impl_base::safe_execute(*this);}

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

protected:

  F        fun_;

  const P1 p1_;

  const P2 p2_;

  const P3 p3_;

};

template<typename F,typename P1,typename P2,typename P3>

inline scope_guard_impl3<F,P1,P2,P3> make_guard(F fun,P1 p1,P2 p2,P3 p3)

{

  return scope_guard_impl3<F,P1,P2,P3>(fun,p1,p2,p3);

}

template<bool cond,typename F,typename P1,typename P2,typename P3>

inline typename null_guard_return<cond,scope_guard_impl3<F,P1,P2,P3> >::type 

make_guard_if_c(F fun,P1 p1,P2 p2,P3 p3)

{

  return typename null_guard_return<cond,scope_guard_impl3<F,P1,P2,P3> >::type(fun,p1,p2,p3);

}

template<typename C,typename F,typename P1,typename P2,typename P3>

inline typename null_guard_return< C::value,scope_guard_impl3<F,P1,P2,P3> >::type 

make_guard_if(F fun,P1 p1,P2 p2,P3 p3)

{

  return make_guard_if_c<C::value>(fun,p1,p2,p3);

}

template<typename F,typename P1,typename P2,typename P3,typename P4>

class scope_guard_impl4:public scope_guard_impl_base

{

public:

  scope_guard_impl4(F fun,P1 p1,P2 p2,P3 p3,P4 p4):

    fun_(fun),p1_(p1),p2_(p2),p3_(p3),p4_(p4){}

  ~scope_guard_impl4(){scope_guard_impl_base::safe_execute(*this);}

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

protected:

  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 scope_guard_impl4<F,P1,P2,P3,P4> make_guard(

  F fun,P1 p1,P2 p2,P3 p3,P4 p4)

{

  return scope_guard_impl4<F,P1,P2,P3,P4>(fun,p1,p2,p3,p4);

}

template<bool cond, typename F,typename P1,typename P2,typename P3,typename P4>

inline typename null_guard_return<cond,scope_guard_impl4<F,P1,P2,P3,P4> >::type 

make_guard_if_c(

  F fun,P1 p1,P2 p2,P3 p3,P4 p4)

{

  return typename null_guard_return<cond,scope_guard_impl4<F,P1,P2,P3,P4> >::type(fun,p1,p2,p3,p4);

}

template<typename C, typename F,typename P1,typename P2,typename P3,typename P4>

inline typename null_guard_return<C::value,scope_guard_impl4<F,P1,P2,P3,P4> >::type 

make_guard_if(

  F fun,P1 p1,P2 p2,P3 p3,P4 p4)

{

  return make_guard_if_c<C::value>(fun,p1,p2,p3,p4);

}

template<class Obj,typename MemFun>

class obj_scope_guard_impl0:public scope_guard_impl_base

{

public:

  obj_scope_guard_impl0(Obj& obj,MemFun mem_fun):obj_(obj),mem_fun_(mem_fun){}

  ~obj_scope_guard_impl0(){scope_guard_impl_base::safe_execute(*this);}

  void execute(){(obj_.*mem_fun_)();}

protected:

  Obj&   obj_;

  MemFun mem_fun_;

};

template<class Obj,typename MemFun>

inline obj_scope_guard_impl0<Obj,MemFun> make_obj_guard(Obj& obj,MemFun mem_fun)

{

  return obj_scope_guard_impl0<Obj,MemFun>(obj,mem_fun);

}

template<bool cond, class Obj,typename MemFun>

inline typename null_guard_return<cond,obj_scope_guard_impl0<Obj,MemFun> >::type 

make_obj_guard_if_c(Obj& obj,MemFun mem_fun)

{

  return typename null_guard_return<cond,obj_scope_guard_impl0<Obj,MemFun> >::type(obj,mem_fun);

}

template<typename C, class Obj,typename MemFun>

inline typename null_guard_return<C::value,obj_scope_guard_impl0<Obj,MemFun> >::type 

make_obj_guard_if(Obj& obj,MemFun mem_fun)

{

  return make_obj_guard_if_c<C::value>(obj,mem_fun);

}

template<class Obj,typename MemFun,typename P1>

class obj_scope_guard_impl1:public scope_guard_impl_base

{

public:

  obj_scope_guard_impl1(Obj& obj,MemFun mem_fun,P1 p1):

    obj_(obj),mem_fun_(mem_fun),p1_(p1){}

  ~obj_scope_guard_impl1(){scope_guard_impl_base::safe_execute(*this);}

  void execute(){(obj_.*mem_fun_)(p1_);}

protected:

  Obj&     obj_;

  MemFun   mem_fun_;

  const P1 p1_;

};

template<class Obj,typename MemFun,typename P1>

inline obj_scope_guard_impl1<Obj,MemFun,P1> make_obj_guard(

  Obj& obj,MemFun mem_fun,P1 p1)

{

  return obj_scope_guard_impl1<Obj,MemFun,P1>(obj,mem_fun,p1);

}

template<bool cond, class Obj,typename MemFun,typename P1>

inline typename null_guard_return<cond,obj_scope_guard_impl1<Obj,MemFun,P1> >::type 

make_obj_guard_if_c(  Obj& obj,MemFun mem_fun,P1 p1)

{

  return typename null_guard_return<cond,obj_scope_guard_impl1<Obj,MemFun,P1> >::type(obj,mem_fun,p1);

}

template<typename C, class Obj,typename MemFun,typename P1>

inline typename null_guard_return<C::value,obj_scope_guard_impl1<Obj,MemFun,P1> >::type 

make_obj_guard_if( Obj& obj,MemFun mem_fun,P1 p1)

{

  return make_obj_guard_if_c<C::value>(obj,mem_fun,p1);

}

template<class Obj,typename MemFun,typename P1,typename P2>

class obj_scope_guard_impl2:public scope_guard_impl_base

{

public:

  obj_scope_guard_impl2(Obj& obj,MemFun mem_fun,P1 p1,P2 p2):

    obj_(obj),mem_fun_(mem_fun),p1_(p1),p2_(p2)

  {}

  ~obj_scope_guard_impl2(){scope_guard_impl_base::safe_execute(*this);}

  void execute(){(obj_.*mem_fun_)(p1_,p2_);}

protected:

  Obj&     obj_;

  MemFun   mem_fun_;

  const P1 p1_;

  const P2 p2_;

};

template<class Obj,typename MemFun,typename P1,typename P2>

inline obj_scope_guard_impl2<Obj,MemFun,P1,P2>

make_obj_guard(Obj& obj,MemFun mem_fun,P1 p1,P2 p2)

{

  return obj_scope_guard_impl2<Obj,MemFun,P1,P2>(obj,mem_fun,p1,p2);

}

template<bool cond, class Obj,typename MemFun,typename P1,typename P2>

inline typename null_guard_return<cond,obj_scope_guard_impl2<Obj,MemFun,P1,P2> >::type

make_obj_guard_if_c(Obj& obj,MemFun mem_fun,P1 p1,P2 p2)

{

  return typename null_guard_return<cond,obj_scope_guard_impl2<Obj,MemFun,P1,P2> >::type(obj,mem_fun,p1,p2);

}

template<typename C, class Obj,typename MemFun,typename P1,typename P2>

inline typename null_guard_return<C::value,obj_scope_guard_impl2<Obj,MemFun,P1,P2> >::type

make_obj_guard_if(Obj& obj,MemFun mem_fun,P1 p1,P2 p2)

{

  return make_obj_guard_if_c<C::value>(obj,mem_fun,p1,p2);

}

template<class Obj,typename MemFun,typename P1,typename P2,typename P3>

class obj_scope_guard_impl3:public scope_guard_impl_base

{

public:

  obj_scope_guard_impl3(Obj& obj,MemFun mem_fun,P1 p1,P2 p2,P3 p3):

    obj_(obj),mem_fun_(mem_fun),p1_(p1),p2_(p2),p3_(p3)

  {}

  ~obj_scope_guard_impl3(){scope_guard_impl_base::safe_execute(*this);}

  void execute(){(obj_.*mem_fun_)(p1_,p2_,p3_);}

protected:

  Obj&     obj_;

  MemFun   mem_fun_;

  const P1 p1_;

  const P2 p2_;

  const P3 p3_;

};

template<class Obj,typename MemFun,typename P1,typename P2,typename P3>

inline obj_scope_guard_impl3<Obj,MemFun,P1,P2,P3>

make_obj_guard(Obj& obj,MemFun mem_fun,P1 p1,P2 p2,P3 p3)

{

  return obj_scope_guard_impl3<Obj,MemFun,P1,P2,P3>(obj,mem_fun,p1,p2,p3);

}

template<bool cond, class Obj,typename MemFun,typename P1,typename P2,typename P3>

inline typename null_guard_return<cond,obj_scope_guard_impl3<Obj,MemFun,P1,P2,P3> >::type

make_obj_guard_if_c(Obj& obj,MemFun mem_fun,P1 p1,P2 p2,P3 p3)

{

  return typename null_guard_return<cond,obj_scope_guard_impl3<Obj,MemFun,P1,P2,P3> >::type(obj,mem_fun,p1,p2,p3);

}

template<typename C, class Obj,typename MemFun,typename P1,typename P2,typename P3>

inline typename null_guard_return<C::value,obj_scope_guard_impl3<Obj,MemFun,P1,P2,P3> >::type

make_obj_guard_if(Obj& obj,MemFun mem_fun,P1 p1,P2 p2,P3 p3)

{

  return make_obj_guard_if_c<C::value>(obj,mem_fun,p1,p2,p3);

}

} /* namespace multi_index::detail */

} /* namespace multi_index */

} /* namespace boost */

#endif