From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-498469-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 41142 invoked by alias); 1 Oct 2015 10:52:39 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <gcc-bugs.gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Received: (qmail 41121 invoked by uid 48); 1 Oct 2015 10:52:36 -0000
From: "frankhb1989 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/67795] New: Wrong code generated for conditional expression with cast
Date: Thu, 01 Oct 2015 10:52:00 -0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: unknown
X-Bugzilla-Keywords:
X-Bugzilla-Severity: normal
X-Bugzilla-Who: frankhb1989 at gmail dot com
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution:
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags:
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-67795-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-SW-Source: 2015-10/txt/msg00024.txt.bz2

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67795

            Bug ID: 67795
           Summary: Wrong code generated for conditional expression with
                    cast
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: frankhb1989 at gmail dot com
  Target Milestone: ---

Case:
// g++ -std=c++1y
#include <iostream>
#include <string>
#include <experimental/string_view>

using namespace std;
using namespace experimental;

string_view&
erase_left(size_t n, string_view& s)
{
        return static_cast<string_view&>(n != 0 ? (s.remove_prefix(n), s) : s);
//      return n != 0 ? (s.remove_prefix(n), s) : s;
}

int main()
{
        string_view sv("abcde");
        cout << erase_left(3, sv).to_string() << endl; // expected "de"
}

The output is garbage, using i686-w64-mingw32-g++ from MSYS2. However,
x86_64-w64-mingw32-clang++ is OK. So I suspect it is a frontend bug.