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- /* 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
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