From b0969362a7a86b83b2d8e6140f70da120d545a01 Mon Sep 17 00:00:00 2001
From: Michael Uleysky <uleysky@poi.dvo.ru>
Date: Tue, 6 Oct 2015 12:46:02 +1000
Subject: [PATCH] OBType and OBTypeM now can accept zero pointer as constructor
 parameter. OBType can be autoconverted to pointer on template parameter
 class.

---
 include/common.h | 60 ++++++++++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/include/common.h b/include/common.h
index e789374..9b88488 100644
--- a/include/common.h
+++ b/include/common.h
@@ -18,7 +18,33 @@ EXPORT std::ostream& COUT(debug_level dl);
 
 typedef std::set<std::string> UsedType;
 
-class EXPORT ObjectBase;
+
+// Base class for all objects
+class EXPORT ObjectBase
+{
+protected:
+// No save by default
+virtual const int8_t* Blob(size_t* size) const { *size=0; return 0; }
+virtual void DeallocBlob(const int8_t* ptr) const {};
+public:
+
+ ObjectBase() = default;
+ ObjectBase(const ObjectBase&) = delete;
+ bool Save(const char* fname) const;
+ // Pure virtual api
+ virtual ~ObjectBase(){}
+ virtual ObjectBase* Copy() const=0;
+ virtual bool Print() const=0;
+ virtual std::string Type() const=0;
+
+ // Virtual api with default functions. Modules types must not override them.
+ virtual std::string Dump() const {return "%"+Type()+"%";}
+ virtual ObjectBase* Evaluate(bool* err) {*err=false; return 0;}
+ virtual ObjectBase* ReplaceVar(const std::string& vname, ObjectBase* ob) {return 0;}
+ virtual void UsedFuncs(UsedType& funcs) const {}
+ virtual void UsedIdents(UsedType& ids) const {}
+};
+
 
 // Template for checking and using ObjectBase derivative classes
 // Checking if arg is pointer on Derived: if(OBType<Derived>(arg))
@@ -31,9 +57,10 @@ class OBType
  OBType() = delete;
  OBType(OBType&&) = delete;
  OBType(OBType&) = delete;
- OBType(const ObjectBase* arg) {if(typeid(*arg)==typeid(O)) p=dynamic_cast<const O*>(arg); else p=0;}
+ OBType(const ObjectBase* arg) {if(0==arg) p=0; else if(typeid(*arg)==typeid(O)) p=dynamic_cast<const O*>(arg); else p=0;}
  const O* operator->() const {return p;}
  operator bool() const {return 0!=p;}
+ operator const O*() const {return p;}
 };
 
 
@@ -67,7 +94,7 @@ class OBTypeM<Func,O1,O...>: public OBTypeM<Func,O...>
   else return OBTypeM<Func,O...>::template F<Res,Args...>(args...);
  }
  public:
- OBTypeM(const ObjectBase* arg):OBTypeM<Func,O...>(arg) {right=(typeid(*arg)==typeid(O1));}
+ OBTypeM(const ObjectBase* arg):OBTypeM<Func,O...>(arg) {if(0==arg) right=false; else right=(typeid(*arg)==typeid(O1));}
  operator bool() const {return right || OBTypeM<Func,O...>::operator bool();}
  template<class Res, class... Args>
  bool Apply(Res& res, Args... args) const
@@ -106,33 +133,6 @@ class OBTypeM<Func>
 };
 
 
-// Base class for all objects
-class EXPORT ObjectBase
-{
-protected:
-// No save by default
-virtual const int8_t* Blob(size_t* size) const { *size=0; return 0; }
-virtual void DeallocBlob(const int8_t* ptr) const {};
-public:
-
- ObjectBase() = default;
- ObjectBase(const ObjectBase&) = delete;
- bool Save(const char* fname) const;
- // Pure virtual api
- virtual ~ObjectBase(){}
- virtual ObjectBase* Copy() const=0;
- virtual bool Print() const=0;
- virtual std::string Type() const=0;
-
- // Virtual api with default functions. Modules types must not override them.
- virtual std::string Dump() const {return "%"+Type()+"%";}
- virtual ObjectBase* Evaluate(bool* err) {*err=false; return 0;}
- virtual ObjectBase* ReplaceVar(const std::string& vname, ObjectBase* ob) {return 0;}
- virtual void UsedFuncs(UsedType& funcs) const {}
- virtual void UsedIdents(UsedType& ids) const {}
-};
-
-
 // Template for objects without specific constructor/destructor
 template<class T>
 class EXPORT ObjectSimple: public ObjectBase