From 7e42ceb42f47453efeedc351b62ba733f56bb24a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Jean-Prost?= <f.jean-prost@infass.com>
Date: Wed, 23 Oct 2019 14:38:24 +0200
Subject: [PATCH] Adding base class for iterator2

class utf8::internal::iterator2 is a base class for utf8::iterator2 and utf8::unchecked::iterator2.
---
 source/utf8/checked.h   | 21 +++++++++++++++
 source/utf8/core.h      | 53 ++++++++++++++++++++++++++++++++++++
 source/utf8/unchecked.h | 59 +++++++++--------------------------------
 3 files changed, 87 insertions(+), 46 deletions(-)

diff --git a/source/utf8/checked.h b/source/utf8/checked.h
index 0567b50..247147d 100644
--- a/source/utf8/checked.h
+++ b/source/utf8/checked.h
@@ -318,6 +318,27 @@ namespace utf8
       }
     }; // class iterator
 
+    //the iterator2 class
+    template <typename octet_iterator>
+    class iterator2 : public utf8::internal::iterator2<octet_iterator> {
+  
+    public:
+  	   using Base = utf8::internal::iterator2<octet_iterator>;
+  	   iterator2 () {}
+  	   iterator2 (octet_iterator begin, octet_iterator end): Base{begin, end, utf8::next<octet_iterator>} {}
+    }; // class iterator2
+  
+    template <typename octet_iterator>
+    inline bool operator==(const iterator2<octet_iterator>& a, const iterator2<octet_iterator>& b)
+    {
+  	     return a.equals(b);
+    }
+    template <typename octet_iterator>
+    inline bool operator!=(const iterator2<octet_iterator>& a, const iterator2<octet_iterator>& b)
+    {
+  	     return !a.equals(b);
+    }         
+
 } // namespace utf8
 
 #if UTF_CPP_CPLUSPLUS >= 201103L // C++ 11 or later
diff --git a/source/utf8/core.h b/source/utf8/core.h
index 244e892..bb3de60 100644
--- a/source/utf8/core.h
+++ b/source/utf8/core.h
@@ -29,6 +29,7 @@ DEALINGS IN THE SOFTWARE.
 #define UTF8_FOR_CPP_CORE_H_2675DCD0_9480_4c0c_B92A_CC14C027B731
 
 #include <iterator>
+#include <functional>
 
 // Determine the C++ standard version.
 // If the user defines UTF_CPP_CPLUSPLUS, use that.
@@ -297,6 +298,58 @@ namespace internal
         return utf8::internal::validate_next(it, end, ignored);
     }
 
+    //the iterator2 class
+    template <typename octet_iterator>
+    class iterator2 : public std::iterator <std::input_iterator_tag, uint32_t> {
+    public:
+	   using function = std::function<uint32_t(octet_iterator&, octet_iterator)>;
+    private:
+      uint32_t cp{};
+      octet_iterator p{};
+      const octet_iterator end{};
+      bool ok{};
+	   const function func{};
+      
+      void read()
+      {
+          ok = p != end;
+          if(ok)
+          {
+              cp = func(p, end);
+          }
+      }
+    public:
+      iterator2 () {}
+      iterator2 (octet_iterator begin_, octet_iterator end_, function f): p{begin_}, end{end_}, func{f} { read(); }
+      uint32_t operator * () const { return cp; }
+      uint32_t* operator -> () const { return &cp; }
+      
+      iterator2& operator ++ ()
+      {
+          if(!ok)
+          {
+              throw std::runtime_error("no such element");
+          }
+          read();
+          return *this;
+      }
+      iterator2 operator ++ (int)
+      {
+          if(!ok)
+          {
+              throw std::runtime_error("no such element");
+          }
+          iterator2 tmp = *this;
+          read();
+          return tmp;
+      }
+      
+      bool equals(const iterator2& a) const
+      {
+          return ok == a.ok && (!ok || p == a.p);
+      }
+    }; // class iterator2
+
 } // namespace internal
 
     /// The library API - functions intended to be called by the users
diff --git a/source/utf8/unchecked.h b/source/utf8/unchecked.h
index ce2d207..b88d287 100644
--- a/source/utf8/unchecked.h
+++ b/source/utf8/unchecked.h
@@ -263,64 +263,31 @@ namespace utf8
           
         //the iterator2 class
         template <typename octet_iterator>
-        class iterator2 : public std::iterator <std::input_iterator_tag, uint32_t> {
+        class iterator2 : public utf8::internal::iterator2<octet_iterator> {
         private:
-          uint32_t cp{};
-          octet_iterator p{};
-          const octet_iterator e{};
-          bool ok{};
-          
-          void read()
-          {
-            ok = p != e;
-            if(ok)
-            {
-              cp = utf8::unchecked::next(p);
-            }
-          }
+		  template <typename T>
+		  struct N {
+			  uint32_t operator()(T& o, T) const {
+				  return utf8::unchecked::next(o);
+           }
+        };
+		  constexpr static N<octet_iterator> NEXT{};
+
         public:
+			 using Base = utf8::internal::iterator2<octet_iterator>;
           iterator2 () {}
-          iterator2 (octet_iterator begin, octet_iterator end): p{begin}, e{end} { read(); }
-          iterator2 (const iterator2& a): cp{a.cp}, p{a.p}, e{a.e}, ok{a.ok} {}
-          
-          uint32_t operator * () const { return cp; }
-          uint32_t* operator -> () const { return &cp; }
-          
-          iterator2& operator ++ ()
-          {
-            if(!ok)
-            {
-              throw std::runtime_error("no such element");
-            }
-            read();
-            return *this;
-          }
-          iterator2 operator ++ (int)
-          {
-             if(!ok)
-             {
-               throw std::runtime_error("no such element");
-             }
-             iterator2 tmp = *this;
-             read();
-             return tmp;
-          }
-          
-          bool equals(const iterator2& a) const
-          {
-            return ok == a.ok && (!ok || p == a.p);
-          }
+          iterator2 (octet_iterator begin, octet_iterator end): Base{begin, end, NEXT} {}
         }; // class iterator2
 
         template <typename octet_iterator>
         inline bool operator==(const iterator2<octet_iterator>& a, const iterator2<octet_iterator>& b)
         {
-          return a.equals(b);
+            return a.equals(b);
         }
         template <typename octet_iterator>
         inline bool operator!=(const iterator2<octet_iterator>& a, const iterator2<octet_iterator>& b)
         {
-          return !a.equals(b);
+            return !a.equals(b);
         }         
 
     } // namespace utf8::unchecked