tests : add missing header

diff --git a/tests/test-sampling.cpp b/tests/test-sampling.cpp
index ebfc17c1822bf0baddab9afcba121c0576ea05be..0e675127f9970b7258a3ad2ce6fe9bcfa25516d4 100644 (file)
--- a/tests/test-sampling.cpp
+++ b/tests/test-sampling.cpp
@@ -5,6 +5,7 @@
 #undef NDEBUG
 #endif
 
+#include <cmath>
 #include <numeric>
 #include <cassert>
 #include <iostream>