[Bug libstdc++/49778] New: Can't take pointer to std::make_pair in c++0x

[bugzilla.gcc.gnu.com at sklep dot czarko.net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49778

           Summary: Can't take pointer to std::make_pair in c++0x
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: bugzilla.gcc.gnu.com@sklep.czarko.net


When g++ is using c++0x standard the following code doesn't compile:

#include <algorithm>
#include <iostream>
#include <iterator>
#include <map>
#include <vector>

int main()
{
    std::vector< int >     inputs1 = { 1, 2, 3 };
    std::vector< int >     inputs2 = { 2, 5, 9 };
    std::map< int, int >   tmp;

    std::transform(
            inputs1.begin(),
            inputs1.end(),
            inputs2.begin(),
            std::inserter( tmp, tmp.begin() ),
            &std::make_pair< int, int >
        );

    for ( const std::pair< int, int > & i : tmp )
    {
        std::cout << "( " << i.first << " -> " << i.second << " )\n";
    }

    return 0;
}

The error is:

In file included from
/usr/lib/gcc/i686-redhat-linux/4.6.0/../../../../include/c++/4.6.0/algorithm:63:0,
                 from a.cpp:1:
/usr/lib/gcc/i686-redhat-linux/4.6.0/../../../../include/c++/4.6.0/bits/stl_algo.h:
In function ‘_OIter std::transform(_IIter1, _IIter1, _IIter2, _OIter,
_BinaryOperation) [with _IIter1 = __gnu_cxx::__normal_iterator<int*,
std::vector<int> >, _IIter2 = __gnu_cxx::__normal_iterator<int*,
std::vector<int> >, _OIter = std::insert_iterator<std::map<int, int> >,
_BinaryOperation = std::pair<int, int> (*)(int&&, int&&)]’:
a.cpp:19:9:   instantiated from here
/usr/lib/gcc/i686-redhat-linux/4.6.0/../../../../include/c++/4.6.0/bits/stl_algo.h:4843:2:
error: invalid initialization of reference of type ‘int&&’ from expression of
type ‘int’



This can be fixed with a custom replacement for std::make_pair and using it
instead:

template < typename T1, typename T2 >
const std::pair< T1, T2 > MakePair( const T1 t1, const T2 t2 )
{
    return std::pair< T1, T2 >( t1, t2 );
}


Note that this is similar to bug 43785 but I don't see here any way of avoiding
explicit template arguments.