`using` declaration for a user-defined literal operator

Is it possible to have a using declaration for the literals operator, operator ""?

E.g.,

#include <chrono>

namespace MyNamespace
{
  constexpr std::chrono::hours operator "" _hr(unsigned long long n){
    return std::chrono::hours{n};
  }

  // ... other stuff in the namespace ...
}

using MyNamespace::operator"";    // DOES NOT COMPILE!

int main()
{
  auto foo = 37_hr;
}

My work-around has been to put these operators in their own nested namespace called literals, which allows using namespace MyNamespace::literals;, but this seems somewhat inelegant, and I don't see why the using directive can't be used for operator functions in the same way as it can for any other functions or types within a namespace.

via Chebli Mohamed