fix: make MUNI_NODISCARD the attribute under GCC 14's C23 too

include/maul-unicode/base.h

@@ -64,14 +64,21 @@ extern "C"
 // MUNI_NODISCARD marks a function whose result must be read: every
 // function that returns a status. The attribute is standard in C23 and
 // C++17 and left out for older dialects. MSVC keeps __cplusplus at
-// 199711L unless /Zc:__cplusplus is given, so _MSVC_LANG is read too.
+// 199711L unless /Zc:__cplusplus is given, so _MSVC_LANG is read too. In
+// C, any dialect after C17 whose compiler has the attribute takes it:
+// GCC 14 reports 202000L in its C23 mode.
 #if (defined(__cplusplus) && __cplusplus >= 201703L) ||                                            \
     (defined(_MSVC_LANG) && _MSVC_LANG >= 201703L)
 #define MUNI_NODISCARD [[nodiscard]]
-#elif !defined(__cplusplus) && defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L
+#elif !defined(__cplusplus) && defined(__STDC_VERSION__) && __STDC_VERSION__ > 201710L &&          \
+    defined(__has_c_attribute)
+#if __has_c_attribute(nodiscard)
 #define MUNI_NODISCARD [[nodiscard]]
 #else
 #define MUNI_NODISCARD
+#endif
+#else
+#define MUNI_NODISCARD
 #endif
 
     // The status a fallible function returns. Zero is success, positive

test/test_base.c

@@ -1,7 +1,8 @@
 // SPDX-License-Identifier: MIT
 // Copyright (c) 2026 Sirac Ozmen
 //
-// Versions and result names, and the layouts of the public types.
+// Versions, result names, the result attribute, and the layouts of the
+// public types.
 
 #include "test_harness.h"
 
@@ -18,6 +19,13 @@
 #include <stddef.h>
 #include <string.h>
 
+// The suites build as C23, where every compiler the family takes has
+// [[nodiscard]], so MUNI_NODISCARD expands to it and a dropped status
+// warns (GCC 14 reports its C23 as 202000L).
+#define TEXT(x)     #x
+#define EXPANDED(x) TEXT(x)
+static_assert(sizeof(EXPANDED(MUNI_NODISCARD)) > 1, "MUNI_NODISCARD is the attribute in C23");
+
 static void TestVersionMatchesHeader(void)
 {
     muniVersion version = muniGetVersion();