size_t needs <cstddef>

diff --git a/source/core/meta.h b/source/core/meta.h
index 923096517dba8132a873de68a79344ab6e2910b1..a13f5cb3a5714de60aba9a7bdc5682370aac110a 100644 (file)
--- a/source/core/meta.h
+++ b/source/core/meta.h
@@ -1,6 +1,8 @@
 #ifndef MSP_CORE_META_H_
 #define MSP_CORE_META_H_
 
+#include <cstddef>
+
 namespace Msp {
 
 template<typename T>