fix move special functions in mem in and outfile (#258)

Correcting a move bug that was introduced earlier.

Author: geo-ant

src/core/openjph/ojph_file.h

@@ -234,12 +234,10 @@ namespace ojph {
 
   private:
 
-    /** @brief A utility to set an instance's fields to default values.
-     *  
-     *  This function is used in the default constructor as well as
-     *  move constructor and assignment.
+    /**
+     * @brief A utility function to swap the contents of two instances
      */
-    static void reset(mem_outfile&) noexcept;
+    void swap(mem_outfile& other) noexcept;
 
     /**
      *  @brief This function expands storage by x1.5 needed space.
@@ -313,6 +311,20 @@ namespace ojph {
     mem_infile() { close(); }
     ~mem_infile() override { }
 
+    mem_infile(mem_infile const&) = delete;
+    mem_infile& operator=(mem_infile const&) = delete;
+
+    /**
+     * Move construction leaves the moved-from value in default constructed state
+     * and transfers ownership of the internal state to the moved-to instance.
+     **/
+    mem_infile(mem_infile &&) noexcept;
+    /**
+     * move assignment with the same ownership transfer semantics as
+     * move construction.
+     **/
+    mem_infile& operator=(mem_infile&&) noexcept;
+
     void open(const ui8* data, size_t size);
 
     //read reads size bytes, returns the number of bytes read
@@ -324,6 +336,9 @@ namespace ojph {
     void close() override { data = cur_ptr = NULL; size = 0; }
 
   private:
+    // swap the contents of two instances
+    void swap(mem_infile&) noexcept;
+
     const ui8 *data, *cur_ptr;
     size_t size;
   };

src/core/others/ojph_file.cpp

@@ -107,14 +107,19 @@ namespace ojph {
   ////////////////////////////////////////////////////////////////////////////
   mem_outfile::mem_outfile()
   {
-    reset(*this);
+    is_open = clear_mem = false;
+    buf_size = used_size = 0;
+    buf = cur_ptr = nullptr;
   }
 
   ////////////////////////////////////////////////////////////////////////////
-  void mem_outfile::reset(mem_outfile& f) noexcept {
-    f.is_open = f.clear_mem = false;
-    f.buf_size = f.used_size = 0;
-    f.buf = f.cur_ptr = nullptr;
+  void mem_outfile::swap(mem_outfile& other) noexcept {
+    std::swap(this->is_open,other.is_open);
+    std::swap(this->clear_mem,other.clear_mem);
+    std::swap(this->buf_size,other.buf_size);
+    std::swap(this->used_size,other.used_size);
+    std::swap(this->buf,other.buf);
+    std::swap(this->cur_ptr,other.cur_ptr);
   }
 
   ////////////////////////////////////////////////////////////////////////////
@@ -128,24 +133,18 @@ namespace ojph {
   }
 
   ////////////////////////////////////////////////////////////////////////////
-  mem_outfile::mem_outfile(mem_outfile&& rhs) noexcept
+  mem_outfile::mem_outfile(mem_outfile&& rhs) noexcept: mem_outfile()
   {
-    reset(*this);
-    std::swap(*this, rhs);
+    this->swap(rhs);
   }
 
   ////////////////////////////////////////////////////////////////////////////
   mem_outfile& mem_outfile::operator=(mem_outfile&& rhs) noexcept
   {
-    if (this == &rhs)
-       return *this;
-
-    if (this->buf)
-      ojph_aligned_free(this->buf);
-
-    reset(*this);
-    std::swap(*this, rhs);
-
+    if (this != &rhs) {
+      mem_outfile tmp(std::move(rhs));
+      this->swap(tmp);
+    }
     return *this;
   }
 
@@ -318,6 +317,22 @@ namespace ojph {
   //
   ////////////////////////////////////////////////////////////////////////////
 
+  ////////////////////////////////////////////////////////////////////////////
+  mem_infile::mem_infile(mem_infile&& rhs) noexcept: mem_infile()
+  {
+    this->swap(rhs);
+  }
+
+  ////////////////////////////////////////////////////////////////////////////
+  mem_infile& mem_infile::operator=(mem_infile&& rhs) noexcept
+  {
+    if (this != &rhs) {
+      mem_infile tmp(std::move(rhs));
+      this->swap(tmp);
+    }
+    return *this;
+  }
+
   ////////////////////////////////////////////////////////////////////////////
   void mem_infile::open(const ui8* data, size_t size)
   {
@@ -376,5 +391,12 @@ namespace ojph {
     return result;
   }
 
+  ////////////////////////////////////////////////////////////////////////////
+  void mem_infile::swap(mem_infile& other) noexcept
+  {
+    std::swap(this->data,other.data);
+    std::swap(this->cur_ptr,other.cur_ptr);
+    std::swap(this->size,other.size);
+  }
 
 }