diff options
| author | Marc Mutz <marc.mutz@kdab.com> | 2020-02-15 20:23:40 +0100 |
|---|---|---|
| committer | Marc Mutz <marc.mutz@kdab.com> | 2020-02-26 07:48:47 +0000 |
| commit | e5acaa12e3cb3f9eb41657eee8146d82fe436093 (patch) | |
| tree | 9e9552e33a6d7a9671983946b862181c09527020 | |
| parent | 3c4078ca02cc438dbe668c4a3819d54134ac75b5 (diff) | |
QObject: treat T* -> bool conversions as narrowing
Following wg21.link/LWG3228, it was found that a proper variant fix
requires that T* -> bool conversions be treated as narrowing
conversions in subclause wg21.link/dcl.init.lst. wg21.link/P1957R2 was
accepted in Prague 2020 as a DR and retroactively applies to older C++
standards.
Since we hard-code the algorithm of [dcl.init.lst], we can and must
add this manually.
[ChangeLog][QtCore][QObject] For the purposes of
QT_NO_NARROWING_CONVERSIONS_IN_CONNECT, pointer
(incl. pointer-to-member) to bool conversions are now considered
narrowing. This matches the resolution of a defect report in C++
itself.
Change-Id: Ifa9a3724c9c8ccd3dd6614928dbbe37477591dc1
Reviewed-by: Ville Voutilainen <ville.voutilainen@qt.io>
| -rw-r--r-- | src/corelib/kernel/qobjectdefs_impl.h | 4 | ||||
| -rw-r--r-- | tests/auto/corelib/kernel/qobject/tst_qobject.cpp | 6 |
2 files changed, 10 insertions, 0 deletions
diff --git a/src/corelib/kernel/qobjectdefs_impl.h b/src/corelib/kernel/qobjectdefs_impl.h index 31ecc8b20d..aed50d6c5a 100644 --- a/src/corelib/kernel/qobjectdefs_impl.h +++ b/src/corelib/kernel/qobjectdefs_impl.h @@ -285,11 +285,15 @@ namespace QtPrivate { { }; + template <typename T> + using is_bool = std::is_same<bool, typename std::decay<T>::type>; + template<typename From, typename To> struct AreArgumentsNarrowedBase<From, To, typename std::enable_if<sizeof(From) && sizeof(To)>::type> : std::integral_constant<bool, (std::is_floating_point<From>::value && std::is_integral<To>::value) || (std::is_floating_point<From>::value && std::is_floating_point<To>::value && sizeof(From) > sizeof(To)) || + ((std::is_pointer<From>::value || std::is_member_pointer<From>::value) && QtPrivate::is_bool<To>::value) || ((std::is_integral<From>::value || std::is_enum<From>::value) && std::is_floating_point<To>::value) || (std::is_integral<From>::value && std::is_integral<To>::value && (sizeof(From) > sizeof(To) diff --git a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp index 21615d6ec4..63d06497ce 100644 --- a/tests/auto/corelib/kernel/qobject/tst_qobject.cpp +++ b/tests/auto/corelib/kernel/qobject/tst_qobject.cpp @@ -7462,6 +7462,12 @@ void tst_QObject::checkArgumentsForNarrowing() FITS(bool, const QObject *&); FITS(int (*)(bool), void (QObject::*)()); + { + // wg21.link/P1957 + NARROWS(char*, bool); + NARROWS(void (QObject::*)(), bool); + } + #undef IS_UNSCOPED_ENUM_SIGNED #undef NARROWS_IF |