Using qreal in QVector2D, QVector3D, QVector4D, etc...

I noticed that QVector2D, QVector3D, QVector4D, etc... use floats as the storage type and I recognize that it was a performance decision to do it this way. I am just wondering why the getters and setters for the structures use qreal as the parameter type instead of floats.

I know that on a mobile system qreal is a float, but on desktop systems qreal is a double. I would like to use these data structures but the conversion from double to float only to be accessed as a double again seems to be overly expensive.

I think it would be best to have all functions use floats instead of qreals in Qt version 5.