HandleDeleter → GenericDeleter and HandleDeleter

utils.hpp

@@ -204,37 +204,41 @@ class SRWLock : public SRWLockBase<SRWLock>
     void on_unlock(bool is_exclusive) {}
 };
 
-struct HandleDeleter
+template <class T, class Deleter, size_t defval = 0>
+struct GenericDeleter
 {
-    void operator()(HANDLE h) noexcept
+    void operator()(T x) noexcept
     {
-        CloseHandle(h);
+        Deleter()(x);
     }
-};
 
-struct FileHandleDeleter : HandleDeleter
-{
     struct pointer
     {
-        pointer(HANDLE h) : value(h) {}
+        pointer(T x) : value(x) {}
 
-        operator HANDLE() const { return value; }
+        operator T() const { return value; }
 
-        pointer(std::nullptr_t = nullptr) : value(INVALID_HANDLE_VALUE) {}
+        pointer(std::nullptr_t = nullptr) : value(recast<T>(defval)) {}
 
-        explicit operator bool() const { return value != INVALID_HANDLE_VALUE; }
+        explicit operator bool() const { return value != recast<T>(defval); }
 
         friend bool operator==(pointer lhs, pointer rhs) { return lhs.value == rhs.value; }
 
-        HANDLE value;
+        T value;
     };
 };
 
-// reset to nullptr
-using GenericHandle = std::unique_ptr<void, HandleDeleter>;
+struct HandleDeleter
+{
+    void operator()(HANDLE h) noexcept
+    {
+        CloseHandle(h);
+    }
+};
+
+using GenericHandle = std::unique_ptr<void, GenericDeleter<HANDLE, HandleDeleter>>;
 
-// reset to INVALID_HANDLE_VALUE
-using FileHandle = std::unique_ptr<void, FileHandleDeleter>;
+using FileHandle = std::unique_ptr<void, GenericDeleter<HANDLE, HandleDeleter, size_t(-1)>>;
 
 struct PagesDeleter
 {