tree 2b5058637a64401074b4ae4fd05a23977b1569e7
parent ea057678c5f603289380e0c2975c477693653c29
author Darius Rueckert <darius.rueckert@fau.de> 1574854870 +0100
committer Darius Rueckert <darius.rueckert@fau.de> 1574871961 +0100

Pass ExpressionRef by const reference instead of by value

Currently there is a bug in the copy constructor of ExpressionRef.
Fixing this bug, will create new expressions each time a copy is
executed. To reduce the amount of copy expression we pass
ExpressionRef by const reference now.

Change-Id: I0f81fb3d08aa4c66b9191f3138650f17023af67e