Centralize the MSVC work-around for std::is_permutation

There's currently only one user, but another one is coming up, so apply DRY
and centralize the work-around for the MSVC warning C4996 on use of 3-arg STL
algorithms in one place.

The code is prepared to handle other algorithms with ease, should any more
crop up.

Change-Id: Ia881888d6a2b5286c6d8d823bc2b76788efad624
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 1 insertions, 15 deletions

diff --git a/src/corelib/tools/qhash.h b/src/corelib/tools/qhash.h
index ee754a79d5..236e433101 100644
--- a/src/corelib/tools/qhash.h
+++ b/src/corelib/tools/qhash.h
@@ -981,22 +981,8 @@ Q_OUTOFLINE_TEMPLATE bool QHash<Key, T>::operator==(const QHash &other) const
             return false;
 
         // Keys in the ranges are equal by construction; this checks only the values.
-        //
-        // When using the 3-arg std::is_permutation, MSVC will emit warning C4996,
-        // passing an unchecked iterator to a Standard Library algorithm. We don't
-        // want to suppress the warning, and we can't use stdext::make_checked_array_iterator
-        // because QHash::(const_)iterator does not work with size_t and thus will
-        // emit more warnings. Use the 4-arg std::is_permutation instead (which
-        // is supported since MSVC 2015).
-        //
-        // ### Qt 6: if C++14 library support is a mandated minimum, remove the ifdef for MSVC.
-        if (!std::is_permutation(thisEqualRangeStart, it, otherEqualRange.first
-#ifdef Q_CC_MSVC
-                                 , otherEqualRange.second
-#endif
-                                 )) {
+        if (!qt_is_permutation(thisEqualRangeStart, it, otherEqualRange.first, otherEqualRange.second))
             return false;
-        }
     }
 
     return true;