add is_string security

src/security/is_string.hpp

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <string>
+#include <variant>
+#include <type_traits>
+
+namespace hack::security
+{
+  template<typename T>
+  struct is_string : public std::disjunction<
+                  std::is_same<char*, typename std::decay_t<T>>,
+                  std::is_same<const char*, typename std::decay_t<T>>,
+                  std::is_same<std::string, typename std::decay_t<T>>> {};
+}