Keep only base/extractor.[cc|h].

base/scope_guard.h

-//
-// Author: Andrei Alexandrescu - andrei@metalanguage.com
-//
-// The code below is based on the following article published in
-// C/C++ Users Journal by Andrei Alexandrescu:
-//
-// http://www.cuj.com/documents/s=8000/cujcexp1812alexandr/alexandr.htm
-//
-// ScopeGuard is useful when you need to perform automatic cleanup of resources.
-// This idiom is important when you want to assemble an operation out of several
-// atomic operations, each of which could fail.
-//
-// Usage
-// ------
-// Scope guard for objects:
-// void f(T& t) {
-//   std::vector<T> v;
-//   v.push_back(t);
-//   ScopeGuard guard = MakeObjGuard(v, &std::vector<T>v::pop_back);
-//   if (!Commit()) {
-//     return;
-//   }
-//   guard.Dismiss();     // removes the t from the vector in the case Commit fails
-// }
-//
-// Scope guard for functions:
-// void open();
-// void close(int i);
-// void g(int i) {
-//   open();
-//   ScopeGuard guard = MakeGuard(close, 0);
-//   if (!read()) {
-//       return;
-//   }
-//   if (!write()) {
-//       return;
-//   }
-// }
-//
-// Using the macros:
-// void g(int i) {
-//   open();
-//   ON_SCOPE_EXIT(close, 0);
-//   if (!read()) {
-//       return;
-//   }
-//   if (!write()) {
-//       return;
-//   }
-// }
-
-// TODO(omaha): provide support to run with or without exceptions enabled.
-// For now it assumes that the code is not throwing exceptions.
-#ifndef SCOPEGUARD_H_
-#define SCOPEGUARD_H_
-
-namespace omaha {
-
-template <class T>
-class RefHolder
-{
-  T& ref_;
-public:
-  RefHolder(T& ref) : ref_(ref) {}
-  operator T& () const
-  {
-    return ref_;
-  }
-private:
-    // Disable assignment - not implemented
-    RefHolder& operator=(const RefHolder&);
-};
-
-template <class T>
-inline RefHolder<T> ByRef(T& t)
-{
-  return RefHolder<T>(t);
-}
-
-class ScopeGuardImplBase
-{
-  ScopeGuardImplBase& operator =(const ScopeGuardImplBase&);
-protected:
-  ~ScopeGuardImplBase()
-  {
-  }
-  ScopeGuardImplBase(const ScopeGuardImplBase& other) throw()
-    : dismissed_(other.dismissed_)
-  {
-    other.Dismiss();
-  }
-  template <typename J>
-  static void SafeExecute(J& j) throw()
-  {
-    if (!j.dismissed_)
-    {
-      // TODO(omaha): assume this does not throw
-      j.Execute();
-    }
-  }
-
-  mutable bool dismissed_;
-public:
-  ScopeGuardImplBase() throw() : dismissed_(false)
-  {
-  }
-  void Dismiss() const throw()
-  {
-    dismissed_ = true;
-  }
-};
-
-typedef const ScopeGuardImplBase& 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);
-}
-
-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);
-}
-
-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);
-}
-
-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);
-}
-
-
-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 <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 <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 <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);
-}
-
-#define CONCATENATE_DIRECT(s1, s2) s1##s2
-#define CONCATENATE(s1, s2) CONCATENATE_DIRECT(s1, s2)
-#define ANONYMOUS_VARIABLE(str) CONCATENATE(str, __LINE__)
-
-#define ON_SCOPE_EXIT ScopeGuard ANONYMOUS_VARIABLE(scopeGuard) = MakeGuard
-#define ON_SCOPE_EXIT_OBJ ScopeGuard ANONYMOUS_VARIABLE(scopeGuard) = MakeObjGuard
-
-}  // namespace omaha
-
-#endif //SCOPEGUARD_H_