Add U8Iterator and Pool base class

include/pd/core/pool.hpp

@@ -0,0 +1,51 @@
+#pragma once
+
+#include <pd/core/common.hpp>
+
+namespace PD {
+template <typename T, typename Alloc = std::allocator<T>>
+class Pool {
+ public:
+  Pool() = default;
+  ~Pool() = default;
+
+  static Pool* Create(size_t size) { return new Pool(size); }
+
+  void Init(size_t size) {
+    pPos = 0;
+    pCap = size;
+    pPool.resize(size);
+  }
+
+  Pool(const Pool&) = delete;
+  Pool(Pool&&) = delete;
+  Pool& operator=(const Pool&) = delete;
+  Pool& operator=(Pool&&) = delete;
+
+  T* Allocate(size_t num = 1) {
+    if (CheckLimits(num)) return nullptr;
+    T* ret = &pPool[pPos];
+    pPos += num;
+    return ret;
+  }
+
+  bool CheckLimits(size_t num) {
+    if ((pPos + num) >= pCap) {
+      throw std::runtime_error(
+          std::format("[PD::Pool]: Trying to allocate {} elements but this is "
+                      "going out of range ({}/{})",
+                      num, pPos + num, pCap));
+      return true;
+    }
+    return false;
+  }
+
+  void Reset() { pPos = 0; }
+
+ private:
+  Pool(size_t size) : pCap(size), pPos(0) { pPool.resize(size); }
+  size_t pCap = 0;
+  size_t pPos = 0;
+  std::vector<T, Alloc> pPool;
+};
+}  // namespace PD