+/// Group contents of an argument if needed
+docstring const protectArgument(docstring & arg, char const l = '[',
+ char const r = ']');
+
+/// Truncates a string with an ellipsis at the end. Leaves str unchanged and
+/// returns false if it is shorter than len. Otherwise resizes str to len, with
+/// U+2026 HORIZONTAL ELLIPSIS at the end, and returns true.
+/// If mid is true, the ellipsis will be put to the mid of the string, and the first
+/// and last half is appended/prepended.
+///
+/// Warning (Unicode): The cases where we want to truncate the text and it does
+/// not end up converted into a QString for UI display must be really
+/// rare. Whenever possible, we should prefer calling QFontMetrics::elidedText()
+/// instead, which takes into account the actual length on the screen and the
+/// layout direction (RTL or LTR). Or a similar function taking into account the
+/// font metrics from the buffer view, which still has to be defined. Or set up
+/// the widgets such that Qt elides the string automatically with the exact
+/// needed width. Recall that not only graphemes vary greatly in width, but also
+/// can be made of several code points. See:
+/// <http://utf8everywhere.org/#myth.strlen>
+///
+/// What is acceptable is when we know that the string is probably going to be
+/// elided by Qt anyway, and len is chosen such that our own ellipsis will only
+/// be displayed in worst-case scenarios.
+///
+/// FIXME: apply those principles in the current code.
+///
+bool truncateWithEllipsis(docstring & str, size_t const len,
+ bool const mid = false);
+