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#include <utility>
#include <vector>
using namespace std;
 
template< class T >
T&& my_forward( typename std::remove_reference<T>::type&& t )
{
    return static_cast<T&&>(t);
}
 
class Library
{
    vector<int> b;
public:
    // hi! only rvalue here :)
    Library( vector<int>&& a):b(std::move(a)){
 
    }
};
 
int main() 
{
    vector<int> v;
    v.push_back(1);
    Library a( my_forward<vector<int>>(v));
    return 0;
}

prog.cpp: In function 'int main()':
prog.cpp:25:41: error: no matching function for call to 'my_forward(std::vector<int>&)'
     Library a( my_forward<vector<int>>(v));
                                         ^
prog.cpp:25:41: note: candidate is:
prog.cpp:6:5: note: template<class T> T&& my_forward(typename std::remove_reference<_From>::type&&)
 T&& my_forward( typename std::remove_reference<T>::type&& t )
     ^
prog.cpp:6:5: note:   template argument deduction/substitution failed:
prog.cpp:25:41: note:   cannot convert 'v' (type 'std::vector<int>') to type 'std::remove_reference<std::vector<int> >::type&& {aka std::vector<int>&&}'
     Library a( my_forward<vector<int>>(v));
                                         ^

Standard output is empty