Undefined reference to sign() when using -O1 or above.
--- a/apricots/all.cpp
+++ b/apricots/all.cpp
@@ -19,5 +19,5 @@
 // Sign function
 
-inline int sign(int n) { return (0 < n) - (n < 0); }
+int sign(int n) { return (0 < n) - (n < 0); }
 
 // Error message for switch statements that shouldn't ever get to default