no idea if this will work

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.20)
 include(cmake/color.cmake)
-set(BLT_VERSION 0.18.39)
+set(BLT_VERSION 0.18.40)
 set(BLT_TEST_VERSION 0.0.1)
 
 set(BLT_TARGET BLT)

include/blt/std/meta.h

@@ -26,7 +26,7 @@
 
 namespace blt::meta
 {
-    template<typename IFirst, typename... IArgs>
+    template<typename IFirst = std::void_t<void>, typename... IArgs>
     struct arg_helper
     {
         using First = IFirst;
@@ -41,7 +41,7 @@ namespace blt::meta
     };
     
     template<>
-    struct arg_helper<void>
+    struct arg_helper<>
     {
         using First = void;
         using Next = void;

libraries/parallel-hashmap

@@ -1 +1 @@
-Subproject commit d88c5e15079047777b418132ece5879e7c9aaa2b
+Subproject commit 8a889d3699b3c09ade435641fb034427f3fd12b6