gintenlib/plane/angle.hpp を微調整

diff --git a/gintenlib/plane/angle.hpp b/gintenlib/plane/angle.hpp
index a0400d8..64aa2c2 100644 (file)
--- a/gintenlib/plane/angle.hpp
+++ b/gintenlib/plane/angle.hpp
@@ -30,6 +30,7 @@
 #include "vector.hpp"
 
 #include "../math.hpp"   // for M_PI
+#include <cassert>
 #include <boost/operators.hpp>
 
 namespace gintenlib