util: Fix copysign redefinition

jschueller · Oct 25, 2024 · a64f72c · a64f72c
1 parent 29211f4
commit a64f72c
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/src/util/nlopt-util.h b/src/util/nlopt-util.h
@@ -37,11 +37,13 @@
 #endif
 
 #ifndef HAVE_COPYSIGN
+#if !defined(__cplusplus) && __STDC_VERSION__ < 199901
    /* not quite right for y == -0, but good enough for us */
 #  define copysign(x, y) ((y) < 0 ? -fabs(x) : fabs(x))
-#elif !defined(__cplusplus) && __STDC_VERSION__ < 199901
+#else
 extern double copysign(double x, double y); /* may not be declared in C89 */
 #endif
+#endif
 
 #ifdef __cplusplus
 extern "C" {