Problem with Locale and Layout

[klusekrules]

In my application I use Polish Locale. We are using ',' as decimal separator.
When I write something like that:

label_->setSize({ "{ ( &.w - &.h - 20 ) * 0.715 , ( &.h - 11 ) * 0.15 }" });

Layout counting it wrongly. '0.715' is interpreted as '0', because function atof expected ',' instead of '.'
But when I set decimal separator as ',' then this expression will be wrongly interpreted.