Fixed linker errors when building pyhton on windows. This fixes a bug that...

Fixed linker errors when building pyhton on windows.  This fixes a bug that was introduced in a recent PR.

Also fixed compiler errors that occurred in visual studio.

dlib/cmake_utils/add_python_module

@@ -126,6 +126,9 @@ else()
 endif()
 
 message(STATUS "USING BOOST_LIBS: ${Boost_LIBRARIES}")
+if (WIN32)
+    message(STATUS "USING PYTHON_LIBS: ${PYTHON_LIBRARIES}")
+endif()
 
 if (CMAKE_COMPILER_IS_GNUCXX)
     # Just setting CMAKE_POSITION_INDEPENDENT_CODE should be enough to set
@@ -150,6 +153,7 @@ macro(add_python_module module_name module_sources )
    TARGET_LINK_LIBRARIES(${module_name}_ ${Boost_LIBRARIES} dlib::dlib)
 
    if(WIN32 AND NOT CYGWIN)
+      TARGET_LINK_LIBRARIES(${module_name}_ ${PYTHON_LIBRARIES})
       SET_TARGET_PROPERTIES( ${module_name}_
          PROPERTIES
          PREFIX ""

dlib/python/numpy.h

@@ -18,7 +18,7 @@ void validate_numpy_array_type (
 )
 {
     using namespace boost::python;
-    const char ch = extract<char>(obj.attr("dtype").attr("char"));
+    const char ch = boost::python::extract<char>(obj.attr("dtype").attr("char"));
 
     if (dlib::is_same_type<T,double>::value && ch != 'd')
         throw dlib::error("Expected numpy.ndarray of float64");

dlib/python/serialize_pickle.h

@@ -45,10 +45,10 @@ struct serialize_pickle : boost::python::pickle_suite
         // UTF-8 encodings.  So instead we access the python C interface directly and use
         // bytes objects.  However, we keep the deserialization code that worked with str
         // for backwards compatibility with previously pickled files.
-        if (extract<str>(state[0]).check())
+        if (boost::python::extract<str>(state[0]).check())
         {
-            str data = extract<str>(state[0]);
-            std::string temp(extract<const char*>(data), len(data));
+            str data = boost::python::extract<str>(state[0]);
+            std::string temp(boost::python::extract<const char*>(data), len(data));
             std::istringstream sin(temp);
             deserialize(item, sin);
         }