external/firebird/0001-Make-comparison-operator-member-functions-const.patch.1

   1 From 15390d75ee6ca429dbbe15ea04214df8a30fbd48 Mon Sep 17 00:00:00 2001
   2 From: Stephan Bergmann <sbergman@redhat.com>
   3 Date: Mon, 21 Oct 2019 17:54:18 +0200
   4 Subject: [PATCH] Make comparison operator member functions const
   5
   6 ...which avoids overload resolution ambiguities in C++20, when a synthesized
   7 candidate of operator == for a reversed-argument rewrite conflicts with the
   8 actual operator ==, due to the asymmetric const-ness of the implicit object
   9 parameter and the RHS parameter.  (As observed with recent Clang 10 trunk with
  10 -std=c++2a when building firebird as part of LibreOffice:
  11
  12 > 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')
  13 >         for (RuntimeStatistics::Iterator iter = stats.begin(); iter != stats.end(); ++iter)
  14 >                                                                ~~~~ ^  ~~~~~~~~~~~
  15 > workdir/UnpackedTarball/firebird/src/jrd/../dsql/../jrd/RuntimeStatistics.h:283:8: note: candidate function
  16 >                 bool operator!=(const Iterator& other)
  17 >                      ^
  18 > workdir/UnpackedTarball/firebird/src/jrd/../dsql/../jrd/RuntimeStatistics.h:278:8: note: candidate function
  19 >                 bool operator==(const Iterator& other)
  20 >                      ^
  21 > workdir/UnpackedTarball/firebird/src/jrd/../dsql/../jrd/RuntimeStatistics.h:278:8: note: candidate function (with reversed parameter order)
  22
  23 )
  24 ---
  25  src/jrd/RuntimeStatistics.h | 4 ++--
  26  1 file changed, 2 insertions(+), 2 deletions(-)
  27
  28 diff --git a/src/jrd/RuntimeStatistics.h b/src/jrd/RuntimeStatistics.h
  29 index 74a03de2ad..fab286ad1a 100644
  30 --- a/src/jrd/RuntimeStatistics.h
  31 +++ b/src/jrd/RuntimeStatistics.h
  32 @@ -290,12 +290,12 @@ public:
  33                 {}
  34
  35         public:
  36 -               bool operator==(const Iterator& other)
  37 +               bool operator==(const Iterator& other) const
  38                 {
  39                         return (m_counts == other.m_counts);
  40                 }
  41
  42 -               bool operator!=(const Iterator& other)
  43 +               bool operator!=(const Iterator& other) const
  44                 {
  45                         return (m_counts != other.m_counts);
  46                 }
  47 --
  48 2.21.0
  49