QString: fix documentation of NUL-termination of unicode(), data(), constData()

(or lack thereof).

* `QString::utf16()` reallocates if `*this` has been constructed using
  `fromRawData()`.

* `QString::data()` ensures a writable string, so will detach from raw
  data.

* `QString::unicode()`, `constData()`, and `data() const` do not. They
  just return `QStringData::data()`, which may point to raw,
  non-NUL-terminated data.

These functions can therefore not possibly have the same behavior, but
were documented the same.

Fix.

Also drop the discussion of operator[](size()), as that, too, was not
correct, and anyone who indexes with op[] beyond size() - 1 should not
rely on proper behavior.

[ChangeLog][QtCore][QString] QString::unicode(), constData() and
`data() const` do not return a NUL-terminated string. This was true
before, but the documentation claimed the opposite.

Change-Id: I1437f57cd02bdf80264e8559608b46aa749c23a8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 0 insertions, 1 deletions

diff --git a/src/corelib/doc/snippets/qstring/main.cpp b/src/corelib/doc/snippets/qstring/main.cpp
index c839c10b84..2ea75526df 100644
--- a/src/corelib/doc/snippets/qstring/main.cpp
+++ b/src/corelib/doc/snippets/qstring/main.cpp
@@ -733,7 +733,6 @@ void Widget::sizeFunction()
     int n = str.size();         // n == 5
     str.data()[0];              // returns 'W'
     str.data()[4];              // returns 'd'
-    str.data()[5];              // returns '\0'
     //! [58]
 }