build python binding error on windows 10,msvc14,python3.6.

复现 Windows 10/MSVC 14/Python 3.6 的构建失败，并检查第 223 行附近的 boost/python/operators.hpp，以及第 40-45 行附近的 operator_l 和 operator_r 声明。确定这段代码在所报告的环境中编译失败的原因，然后验证 Python binding 在该环境中能够成功构建，且不会引入所列出的错误。

D:\local\boost_1_67_0\boost/python/operators.hpp(223): error C2065: "op_": undeclared identifier
D:\local\boost_1_67_0\boost/python/operators.hpp(223): error C2059: Syntax error: ">"
D:\local\boost_1_67_0\boost/python/operators.hpp(223): error C2976: "boost::python::detail::operator_l": Template parameters are too few
D:\local\boost_1_67_0\boost/python/operators.hpp(40): note: See the declaration of "boost::python::detail::operator_l"
D:\local\boost_1_67_0\boost/python/operators.hpp(223): error C2913: Explicit specialization; "boost::python::detail::operator_l" is not a specialization of a class template
D:\local\boost_1_67_0\boost/python/operators.hpp(223): error C2065: "op_": undeclared identifier
D:\local\boost_1_67_0\boost/python/operators.hpp(223): error C2059: Syntax error: ">"
D:\local\boost_1_67_0\boost/python/operators.hpp(223): error C2976: "boost::python::detail::operator_r": Template parameters are too few
D:\local\boost_1_67_0\boost/python/operators.hpp(45): note: See the declaration of "boost::python::detail::operator_r"
D:\local\boost_1_67_0\boost/python/operators.hpp(223): error C2913: Explicit specialization; "boost::python::detail::operator_r" is not specialization of class template
D:\local\boost_1_67_0\boost/python/operators.hpp(224): error C2913: Explicit customization; "boost::python::detail::operator_l" is not a specialization of the class template
D:\local\boost_1_67_0\boost/python/operators.hpp(224): error C2913: Explicit customization; "boost::python::detail::operator_r" is not a specialization of the class template