adding missing header include

src/Classic/TrimCoils/OpalTrimCoil.h

@@ -2,6 +2,7 @@
 #define OPAL_TRIM_COIL_H
 
 #include <string>
+#include <memory>
 #include "AbstractObjects/Definition.h"
 
 class TrimCoil;
@@ -45,7 +46,7 @@ public:
 
     /// Actual implementation
     std::unique_ptr<TrimCoil> trimcoil_m;
-    
+
 private:
 
     ///@{ Not implemented.
@@ -61,4 +62,4 @@ inline Inform &operator<<(Inform &os, const OpalTrimCoil &b) {
     return b.print(os);
 }
 
-#endif // OPAL_TRIM_COIL_H
+#endif // OPAL_TRIM_COIL_H
\ No newline at end of file