3 files changed, 70 insertions, 0 deletions
diff --git a/asl/meta/internal/quals.hpp b/asl/meta/internal/quals.hpp
new file mode 100644
index 0000000..869cc89
--- /dev/null
+++ b/asl/meta/internal/quals.hpp
@@ -0,0 +1,16 @@
+#pragma once
+
+#include "asl/meta/types.hpp"
+
+namespace asl::internal {
+
+template<typename T> struct const_helper { using add = const T; using remove = T; };
+template<typename T> struct const_helper<const T> { using add = const T; using remove = T; };
+
+template<typename T> concept is_const = same<T, typename internal::const_helper<T>::add>;
+
+template<typename T> struct volatile_helper { using add = volatile T; using remove = T; };
+template<typename T> struct volatile_helper<volatile T> { using add = volatile T; using remove = T; };
+
+} // namespace asl::internal
+
diff --git a/asl/meta/internal/refs.hpp b/asl/meta/internal/refs.hpp
new file mode 100644
index 0000000..b21a0a1
--- /dev/null
+++ b/asl/meta/internal/refs.hpp
@@ -0,0 +1,45 @@
+#pragma once
+
+#include "asl/meta/types.hpp"
+
+namespace asl::internal {
+    
+template<typename T, typename = void>
+inline constexpr bool is_referenceable = false;
+
+template<typename T>
+inline constexpr bool is_referenceable<T, void_t<T&>> = true;
+
+template<typename T, bool = is_referenceable<T>>
+struct as_ref_helper { using lvalue = T; using rvalue = T; };
+
+template<typename T>
+struct as_ref_helper<T, true> { using lvalue = T&; using rvalue = T&&; };
+
+template<typename T> struct un_ref_helper { using type = T; };
+template<typename T> struct un_ref_helper<T&> { using type = T; };
+template<typename T> struct un_ref_helper<T&&> { using type = T; };
+
+template<typename T>
+struct is_ref_helper
+{
+    static inline constexpr bool lref = false;
+    static inline constexpr bool rref = false;
+};
+
+template<typename T>
+struct is_ref_helper<T&>
+{
+    static inline constexpr bool lref = true;
+    static inline constexpr bool rref = false;
+};
+
+template<typename T>
+struct is_ref_helper<T&&>
+{
+    static inline constexpr bool lref = false;
+    static inline constexpr bool rref = true;
+};
+
+} // namespace asl::internal
+
diff --git a/asl/meta/internal/types.hpp b/asl/meta/internal/types.hpp
new file mode 100644
index 0000000..f635de5
--- /dev/null
+++ b/asl/meta/internal/types.hpp
@@ -0,0 +1,9 @@
+#pragma once
+
+namespace asl::internal {
+
+template<typename U, typename V> inline constexpr bool is_same = false;
+template<typename T> inline constexpr bool is_same<T, T> = true;
+
+} // namespace asl::internal
+