Initial commit - restart from existing code

lib/All/entt/test/common/pointer_stable.h

@@ -0,0 +1,21 @@
+#ifndef ENTT_COMMON_POINTER_STABLE_H
+#define ENTT_COMMON_POINTER_STABLE_H
+
+namespace test {
+
+struct pointer_stable {
+    static constexpr auto in_place_delete = true;
+    int value{};
+};
+
+[[nodiscard]] inline bool operator==(const pointer_stable &lhs, const pointer_stable &rhs) {
+    return lhs.value == rhs.value;
+}
+
+[[nodiscard]] inline bool operator<(const pointer_stable &lhs, const pointer_stable &rhs) {
+    return lhs.value < rhs.value;
+}
+
+} // namespace test
+
+#endif