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From: "mpolacek at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/94695] New: Implement -Wrange-loop-analysis
Date: Tue, 21 Apr 2020 14:37:43 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94695

            Bug ID: 94695
           Summary: Implement -Wrange-loop-analysis
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mpolacek at gcc dot gnu.org
  Target Milestone: ---

This options contains a sub-option -Wrange-loop-construct which warns about:

#include <string>
#include <vector>

int main()
{
    std::vector<std::string> lol;
    for (const auto it : lol) { }
}

<source>:7:21: warning: loop variable 'it' creates a copy from type 'const
std::__cxx11::basic_string<char>' [-Wrange-loop-construct]

    for (const auto it : lol) { }

                    ^

<source>:7:10: note: use reference type 'const std::__cxx11::basic_string<c=
har>
&' to prevent copying

    for (const auto it : lol) { }

         ^~~~~~~~~~~~~~~

                    &

1 warning generated.

We should consider adding something like that, too, in GCC 11.=