Temporary: adding Singleton pattern in order to bypass tesseract iterators and lists

src/ccstruct/tabletransfer.hpp

@@ -0,0 +1,42 @@
+#pragma once
+#include <memory>
+#include <vector>
+#include "rect.h"
+
+
+/// Structure for data transfer from table detector 
+struct MyTable {
+  TBOX box;
+  std::vector<TBOX> rows;
+  std::vector<TBOX> cols;
+};
+
+/** \brief You can use this small template function to ensure that one and
+ *   only one object of type T exists. It implements the Singleton Pattern.
+ *
+ * T must be default-constructable.
+ * Usage examples:
+ *   A& a = uniqueInstance<A>();
+ *   a.xyz();
+ *   uniqueInstance<A>(make_unique<A>(42)); // replace instance
+ *   a.foo();
+ * or
+ *   uniqueInstance<A>().xyz();
+ */
+template<typename T>
+T& uniqueInstance(std::unique_ptr<T> new_instance = nullptr)
+{
+  static std::unique_ptr<T> _instance = std::make_unique<T>();
+
+  if(new_instance)
+    _instance = std::move(new_instance);
+
+  return *_instance.get();
+}
+
+/// return const version of \see uniqueInstance
+template<typename T>
+const T& constUniqueInstance(std::unique_ptr<T> new_instance = nullptr)
+{
+  return uniqueInstance<T>(std::move(new_instance));
+}