add constexpr_tuple_accumulate.hpp

Author: robertshepherdcpp

constexpr_tuple_accumulate.hpp

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <tuple>  // std::tuple
+
+namespace mlib {
+    template <typename... Ts>
+    constexpr auto constexpr_tuple_accumulate(std::tuple<Ts...> tup) {
+        return[=]<std::size_t... indexes>(std::index_sequence<indexes...>) {
+            return (std::get<indexes>(tup) + ...);
+        }(std::make_index_sequence<sizeof...(Ts)>{});
+    }
+}  // namespace mlib