[Bug fortran/52347] -Wno-tabs -Wall -Wno-tabs still warns about tabs

["manu at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52347

--- Comment #3 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
(In reply to Simon Richter from comment #2)
> In 4.8, this causes build failures for me:
> 
> $ g++ -g -Wall -W -Werror -Wno-unused -I. -o stage1/tree_bison_lex.o -c
> tree_bison_lex.cpp
> tree_bison_lex.cpp:1744:13: error: unused parameter 'yyscanner'
> [-Werror=unused-parameter]

Could you attach a self-contained preprocessed testcase?
See http://gcc.gnu.org/bugs/
>From gcc-bugs-return-424380-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Fri Jun 14 21:41:19 2013
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From: "gdjss2728 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/57619] New: std::unordered_map and std::unordered_multimap::insert invoking std::pair move constructor
Date: Fri, 14 Jun 2013 21:41:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idW619

            Bug ID: 57619
           Summary: std::unordered_map and std::unordered_multimap::insert
                    invoking std::pair move constructor
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gdjss2728 at gmail dot com

The following code is invoking the std::pair move constructor:

int main ()
{
    std::unordered_map<std::string, std::string> mymap;
    std::unordered_multimap<std::string, std::string> mymultimap;
    std::pair<std::string, std::string> mypair{std::string("key"),
std::string("value")};
    mymultimap.insert(mypair); // std::pair move constructor invoked here
    mymap.insert(mypair); // strings already moved out!
}

This seems related to http://gcc.gnu.org/bugzilla/show_bug.cgi?idS657.

As far as I can tell, overload resolution is choosing `insert(_Pair&& __x)`
over `insert(const value_type& __x)`. Since this is an lvalue, the latter
should be chosen. This happens for std::unordered_map::insert and
std::unordered_multimap::insert.