user readable error message

Sample/Scattering/IFormFactor.cpp

@@ -66,9 +66,8 @@ IFormFactor* IFormFactor::createSlicedFormFactor(ZLimits limits, const IRotation
         return nullptr;
     if (canSliceAnalytically(rot))
         return sliceFormFactor(limits, rot, translation);
-    throw std::runtime_error(className()
-                             + "::createSlicedFormFactor error: not supported for "
-                               "the given rotation!");
+    throw std::runtime_error(
+        "Slicing of " + className() + " not supported for the given rotation!");
 }
 
 Eigen::Matrix2cd IFormFactor::thePolFF(const WavevectorInfo&) const