minor refactor

src/delegates.h

@@ -10,5 +10,8 @@ using wstringsupplier = std::function<std::wstring()>;
 using wstringconsumer = std::function<void(const std::wstring&)>;
 using doublesupplier = std::function<double()>;
 using doubleconsumer = std::function<void(double)>;
+using boolsupplier = std::function<bool()>;
+using boolconsumer = std::function<void(bool)>;
+using wstringchecker = std::function<bool(const std::wstring&)>;
 
 #endif // DELEGATES_H_