Re: C++ PATCH for c++/88136, -Wdeprecated-copy too noisy

[Ville Voutilainen <ville.voutilainen@gmail.com>]

On Sat, 8 Dec 2018 at 20:05, Ville Voutilainen
<ville.voutilainen@gmail.com> wrote:

> > New compiler releases will usually include new warnings that require
> > some code modification to accommodate.  Why is this one particularly
> > problematic?
>
> I don't think it's any more problematic than any other warning that
> introduces new errors for fools that build with -Wall and -Werror.
> But considering that those errors are false positives, and that
> turning them off will in some cases require writing boiler-plate
> (defaulted assignments), I would merely prefer having another release
> round to get fixes for my codebase out in the wild.

For what it's worth, I find it unfortunate that this deprecation and
its resulting warnings end up
making the decision on whether a "rule of 5" must be followed; correct
code needs to be adjusted
to cope with a fairly stylistic matter, with false positives and all.

I'll vote with my feet:

diff --git a/mkspecs/features/qt_common.prf b/mkspecs/features/qt_common.prf
index 4ad9946..3ba7eff 100644
--- a/mkspecs/features/qt_common.prf
+++ b/mkspecs/features/qt_common.prf
@@ -89,6 +89,8 @@ clang {
     greaterThan(QT_GCC_MAJOR_VERSION, 5): QMAKE_CXXFLAGS_WARN_ON +=
-Wshift-overflow=2 -Wduplicated-cond
     # GCC 7 has a lot of false positives relating to this, so disable
completely
     greaterThan(QT_GCC_MAJOR_VERSION, 6): QMAKE_CXXFLAGS_WARN_ON +=
-Wno-stringop-overflow
+    # GCC 9 has a lot of false positives relating to this, so disable
completely
+    greaterThan(QT_GCC_MAJOR_VERSION, 8): QMAKE_CXXFLAGS_WARN_ON +=
-Wno-deprecated-copy
 }