Set width to match constraints in ConstraintLayout

match_parent is not supported, so use android:layout_width="0dp". With 0dp, you can think of your constraints as 'scalable' rather than 'filling whats left'.

Also, 0dp can be defined by a position, where match_parent relies on it's parent for it's position (x,y and width, height)

match_parent is not allowed. But you can actually set width and height to 0dp and set either top and bottom or left and right constraints to "parent".

So for example if you want to have the match_parent constraint on the width of the element, you can do it like this:

<TextView
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintEnd_toEndOf="parent"/>