From 68d04eb43f620f884d6c9f12e1b796e908d57621 Mon Sep 17 00:00:00 2001
From: "matthias@arch" <matthiasqui@protonmail.com>
Date: Mon, 30 Jan 2023 16:05:53 +0100
Subject: [PATCH] Added IsPointerToType

---
 src/concepts.hpp | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/concepts.hpp b/src/concepts.hpp
index 4bbcc2a..d38e006 100644
--- a/src/concepts.hpp
+++ b/src/concepts.hpp
@@ -1,8 +1,12 @@
 #pragma once
 
 #include <concepts>
+#include <cstddef>
 #include <ranges>
 
+#include <memory>
+#include <type_traits>
+
 namespace gz::util {
     /// Satisfied when T is in PackTypes
     template<typename T, typename... PackTypes>
@@ -23,6 +27,19 @@ namespace gz::util {
 	template<typename T, typename ValueType>
 	concept ContiguousRange = std::ranges::contiguous_range<T> and std::same_as<std::ranges::range_value_t<T>, ValueType>;
 
+    /// ObjectType accessible via *t and convertible to bool
+    template<typename T, typename ObjectType>
+    concept IsPointerToType = requires (T t/*, std::ptrdiff_t idx*/) {
+        /* { t.operator*() } -> std::same_as<std::add_lvalue_reference_t<ObjectType>>; */
+        /* { t.operator->() } -> std::same_as<std::add_pointer_t<ObjectType>>; */
+        /* { t.operator[](idx) } -> std::same_as<std::add_lvalue_reference_t<ObjectType>>; */
+        { *t } -> std::same_as<std::add_lvalue_reference_t<ObjectType>>;
+        /* { t-> } -> std::same_as<std::add_lvalue_reference_t<ObjectType>>; */
+        { static_cast<bool>(t) };
+    };
+    static_assert(IsPointerToType<std::shared_ptr<int>, int>, "");
+    static_assert(IsPointerToType<int*, int>, "");
+
  
 }