add identificato pattern

bin/main.cpp

@@ -7,6 +7,7 @@
 #include "hack/math/max.hpp"
 
 #include "hack/patterns/ring_buffer.hpp"
+#include "hack/patterns/identificator.hpp"
 
 auto main(int argc, char *argv[]) -> int
 { 
@@ -25,6 +26,16 @@ auto main(int argc, char *argv[]) -> int
     hack::log()(v);
   }
 
+  // patterns::identificator
+  {
+    struct a : public hack::patterns::identificator<>
+    {} aa;
+    a bb;
+    a cc;
+    a dd;
+    hack::log()(aa.m_id, bb.m_id, cc.m_id, dd.m_id);
+  }
+
   // range::sort
   {
     std::vector<int> v { 4, 4, 6, 1, 4, 3, 2 };

src/hack/patterns/identificator.hpp

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <cstddef>
+
+namespace hack::patterns
+{
+  template<typename T = std::size_t>
+  class identificator 
+  {
+    public:
+      identificator() { m_id = m_counter; ++m_counter; }
+
+    public:
+     T m_id;
+
+    private:
+      static inline T m_counter = 0;
+  };
+}