[Bug libstdc++/87037] New: vector :: erase return value should be marked "must use"

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87037

            Bug ID: 87037
           Summary: vector :: erase return value should be marked "must
                    use"
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

Given the following C++ source code

# include <vector>

using namespace std;

void f( vector < int > & vec)
{
        for (auto i = vec.begin(); i != vec.end(); ++i)
        {
                vec.erase( i);
        }
}

then there is an obvious bug that the return value from the erase
isn't used for loop control. gcc seems strangely silent on the issue:

$ ~/gcc/results.263644/bin/gcc -c -g -O2 -Wall -Wextra aug21a.cc
$