use pybind11::literals namespace

src/common.h

@@ -13,6 +13,7 @@
 #include <tuple>
 
 namespace py = pybind11;
+using namespace pybind11::literals;
 
 #if PY_MAJOR_VERSION >= 3
 #define PY_DIV "__truediv__"

src/utility/shortestPaths.cpp

@@ -3,7 +3,6 @@
 
 #include <string>
 
-using namespace pybind11::literals;
 
 void define_ksp(py::module& m) {