mirror of https://github.com/qt/qtbase.git
bb0a616260
Use P0608's trick to detect convertibility without narrowing;
and now that we can depend on C++17, use its features.
First, this moves the burden of detecting a narrowing conversion on
the compiler, rather than us maintaining a complicated series
of checks. Of course, this exposes
* bugs in compilers (e.g. GCC < 9 thinks that float->bool is not
narrowing;
* behavior still not (widely) implemented (pointer to bool
conversions are narrowing, P1957);
* interesting compiler choices, e.g. GCC 9 thinks that unscoped
enumerations are non-narrowing convertible to a datatype big
enum to contain all the _enumerators_, even if the underlying
type of the enum (and/or its sizeof()) is wider than the target
datatype.
Second, it allows to detect conversions that have a narrowing
conversion as an intermediate step. Given a type like
struct Bad { operator double() const; };
then an object of type Bad is implictly convertible to a type
like int via a narrowing conversion. Therefore, a connection
is possible between a signal carrying a Bad and a slot accepting
an int. We can now detect and block this.
Tests regarding scoped enumerations have been dropped,
for the simple reason that a scoped enumeration is not
implictly convertible to an integral type, so we don't have
that detection (it would constantly fail). Scoped enumerations
do not take part in narrowing conversions anyhow, cf. [dcl.init.list].
[ChangeLog][QtCore][QObject] The detection of narrowing conversions
when calling QObject::connect() when
QT_NO_NARROWING_CONVERSIONS_IN_CONNECT now takes also
into account user-defined implicit conversions that undergo
through a narrowing conversion.
Change-Id: Ie09d59203fe6283378b36dfbc54de1d58098ef51
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
|
||
|---|---|---|
| .. | ||
| auto | ||
| baselineserver | ||
| benchmarks | ||
| global | ||
| libfuzzer | ||
| manual | ||
| shared | ||
| testserver | ||
| .prev_CMakeLists.txt | ||
| CMakeLists.txt | ||
| README | ||
| tests.pro | ||
README
This directory contains autotests and benchmarks based on Qt Test. In order
to run the autotests reliably, you need to configure a desktop to match the
test environment that these tests are written for.
Linux X11:
* The user must be logged in to an active desktop; you can't run the
autotests without a valid DISPLAY that allows X11 connections.
* The tests are run against a KDE3 or KDE4 desktop.
* Window manager uses "click to focus", and not "focus follows mouse". Many
tests move the mouse cursor around and expect this to not affect focus
and activation.
* Disable "click to activate", i.e., when a window is opened, the window
manager should automatically activate it (give it input focus) and not
wait for the user to click the window.