From 15390d75ee6ca429dbbe15ea04214df8a30fbd48 Mon Sep 17 00:00:00 2001 From: Stephan Bergmann Date: Mon, 21 Oct 2019 17:54:18 +0200 Subject: [PATCH] Make comparison operator member functions const ...which avoids overload resolution ambiguities in C++20, when a synthesized candidate of operator == for a reversed-argument rewrite conflicts with the actual operator ==, due to the asymmetric const-ness of the implicit object parameter and the RHS parameter. (As observed with recent Clang 10 trunk with -std=c++2a when building firebird as part of LibreOffice: > workdir/UnpackedTarball/firebird/src/jrd/inf.cpp:1139:62: error: use of overloaded operator '!=' is ambiguous (with operand types 'RuntimeStatistics::Iterator' and 'Jrd::RuntimeStatistics::Iterator') > for (RuntimeStatistics::Iterator iter = stats.begin(); iter != stats.end(); ++iter) > ~~~~ ^ ~~~~~~~~~~~ > workdir/UnpackedTarball/firebird/src/jrd/../dsql/../jrd/RuntimeStatistics.h:283:8: note: candidate function > bool operator!=(const Iterator& other) > ^ > workdir/UnpackedTarball/firebird/src/jrd/../dsql/../jrd/RuntimeStatistics.h:278:8: note: candidate function > bool operator==(const Iterator& other) > ^ > workdir/UnpackedTarball/firebird/src/jrd/../dsql/../jrd/RuntimeStatistics.h:278:8: note: candidate function (with reversed parameter order) ) --- src/jrd/RuntimeStatistics.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/jrd/RuntimeStatistics.h b/src/jrd/RuntimeStatistics.h index 74a03de2ad..fab286ad1a 100644 --- a/src/jrd/RuntimeStatistics.h +++ b/src/jrd/RuntimeStatistics.h @@ -290,12 +290,12 @@ public: {} public: - bool operator==(const Iterator& other) + bool operator==(const Iterator& other) const { return (m_counts == other.m_counts); } - bool operator!=(const Iterator& other) + bool operator!=(const Iterator& other) const { return (m_counts != other.m_counts); } -- 2.21.0