Fixed detection of Char * addends as eligible for sys_string addition

Author: gershnik

lib/inc/sys_string/sys_string.h

@@ -62,10 +62,14 @@ namespace sysstr
     };
 
     template<class T, class Storage>
-    concept addable = sys_string_or_char<T, Storage> || (
-                            std::ranges::forward_range<T> &&
-                            has_utf_encoding<std::ranges::range_value_t<T>>
-                      );
+    concept addable = sys_string_or_char<T, Storage> || 
+                  (
+                        std::ranges::forward_range<T> &&
+                        has_utf_encoding<std::ranges::range_value_t<T>>
+                  ) || (
+                        std::is_pointer_v<std::decay_t<T>> &&
+                        has_utf_encoding<std::remove_const_t<std::remove_pointer_t<std::decay_t<T>>>>
+                  );
 }
 
 namespace sysstr::util

test/test_general.cpp

@@ -740,6 +740,9 @@ TEST_CASE( "Addition" ) {
     CHECK((("a"sv + S("b")) + (S("💾") + "💿"s)) + ("🜇"s + S("⏰")) == S("ab💾💿🜇⏰"));
     sys_string result = S("a") + U'b' + "cd" + "ef"s + u"gh"sv + U"ij" + std::vector{'k', 'l'};
     CHECK(result == S("abcdefghijkl"));
+
+    const char * foo = "abc";
+    CHECK(S("x") + foo == "xabc");
 }
 
 TEST_CASE( "c_str" ) {