When assigning the lambdas directly to a function_ref their lifetime is
limited to that of the expression. Store them on the stack first to
avoid the UB.
Fixes: QTBUG-104419
Pick-to: 6.4
Change-Id: I3c85ac683b0bd7768b646dc9d0a1ed4dd173e6f3
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
This reverts commit b9cce12e76, which
broke
function_ref<void(int)> f = [](int i) { return i; };
ie. swallowing of return types.
We could maybe implement the same without invoke_r, with the same
manual if-constexpr that invoke_r has, but it would be a pointless
duplication across the two thunks we have, so just use invoke_r.
Add tests.
Pick-to: 6.4
Task-number: QTBUG-103739
Change-Id: I6034f05d813c06a25e8058ded5b6b62f3ca858b4
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
This is an implementation of function_ref, which has been proposed for
inclusion into C++23, but has not been accepted, yet, which is why we
place it in namespace qxp (for eXPerimental) instead of q23.
The implementation is based on wg21.link/P0792r9, which, at the time
of writing, is the latest revision of the paper. It will be used in
both QTestLib and qmldom.
Fixes: QTBUG-103739
Change-Id: I52723eca28f7ac02ce7ce51928361d81ae5c92b1
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
