Fixed missing inclusion for <new>

Sp3EdeR · Sp3EdeR · commit cc273e95f484 · 2025-12-08T12:49:54.000+01:00
This fixes a build error on GCC 14+ and Clang 19+
diff --git a/include/singleton.hpp b/include/singleton.hpp
@@ -2,6 +2,7 @@
 #define TESTABLE_SINGLETON_INCLUDED_H
 
 #include <mutex>
+#include <new>
 #include <utility>
 
 /// Implements the singleton pattern, but makes unit testing easy.
