QByteArray, QString, QStringRef: Add chopped()

We have two functions to get a substring without doing some
calculations involving size():

- mid(p):    mid(p, size() - p)
- right(n) : mid(size() - n, n)

(left does not involve size(), so isn't in that set). What was missing
was a name for

- f(n): mid(0, size() - n)

As an action, it's called chop(), so call the transformation version
chopped().

I made chopped(n), n < 0 or n > size(), undefined, because QString(Ref)
::left() is broken[1], while the QByteArray implementation is not. This
is the only way to get consistent behavior among the three classes.

I's also the correct thing to do.

[1] instead of returning the empty string for negative indexes, it
returns the whole string.

[ChangeLog][QtCore][QString/QStringRef/QByteArray] Added chopped(n), a
const version of chop(n).

Change-Id: I6c2c5b16e0060fa924ced5860f21f2d0f23bd023
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Anton Kudryavtsev <antkudr@mail.ru>

0 files changed, 0 insertions, 0 deletions