PushValue takes a new value, not a delta value. Thus something like
the following does not do what you think it does:

    PushValue increase(myCounter, +1);

This always sets the value to 1 and resets the old value at exit.
To push a delta value, you need to be more verbose:

    PushValue increase(myCounter, myCounter + 1);

This was while reviewing new code in review request 111796. Shows
how much good a code review can do! I checked all other uses of
PushValue and they seem to work as intended.