map_indexing_suite doesn't work with std::unordered_map<std::string, std::vector<double>> for MSVC 14.2

從 boost/python/suite/indexing/map_indexing_suite.hpp 第 155 行開始，使用巢狀的 std::unordered_map 範例透過 MSVC v142 重現建置。將其與報告中描述的 std::map 和 string 值案例進行比較。當 map_indexing_suite 範例在巢狀 unordered_map 設定下成功建置時，即表示完成。

This works on MSVC 14.1 (Visual Studio 17):

#define BOOST_PYTHON_STATIC_LIB

#include <boost/python.hpp>
#include <boost/python/suite/indexing/map_indexing_suite.hpp>
#include <boost/python/suite/indexing/vector_indexing_suite.hpp>
#include <string>
#include <unordered_map>
#include <vector>

BOOST_PYTHON_MODULE(HelloBoostPython)
{
    using namespace boost::python;

    class_<std::vector<double>>("DoubleVector")
        .def(vector_indexing_suite<std::vector<double>>())
        ;

    class_<std::unordered_map<std::string, std::string>>("StringVecMap")
        .def(map_indexing_suite<std::unordered_map<std::string, std::vector<double>>>())
        ;
}

But fails when building against the v142 (VS 19) Platform Toolset:

Severity	Code	Description	Project	File	Line	Suppression State
Error	C2039	'key_comp': is not a member of 'std::unordered_map<std::string,std::vector<double,std::allocator<double>>,std::hash<std::string>,std::equal_to<std::string>,std::allocator<std::pair<const std::string,std::vector<double,std::allocator<double>>>>>'	HelloBoostPython	C:\Misc\boost_1_71_0\boost\python\suite\indexing\map_indexing_suite.hpp	155	

Change std::unordered_map to std::map and it works.

Change std::unordered_map<std::string, std::vector<double>> to std::unordered_map<std::string, std::string>> and it works.