Q:

Can't add element to bsoncxx document

Can't add an element to bsoncxx document
    auto doc = bsoncxx::builder::basic::document{};

    const char* key = "asd";
    const char* value = "123";

    doc.append(kvp(key, value));

bsoncxx::v_noabi::builder::basic::sub_document::append_(bsoncxx::v_noabi::builder::concatenate_doc)': cannot convert argument 1 from '_Ty' to 'bsoncxx::v_noabi::builder::concatenate_doc'
1>          with
1>          [
1>              _Ty=std::tuple<const char *&,const char *&>
1>          ]

but this code is work
    auto doc = bsoncxx::builder::basic::document{};

    const char* key = "asd";
    const char* value = "123";

    doc.append(kvp("asd", value));

mongo cxx driver v3.3.1

A:

This code is work 
#include <bsoncxx/stdx/string_view.hpp>

    auto doc = bsoncxx::builder::basic::document{};

    bsoncxx::stdx::string_view key = "asd";
    const char* value = "123";

    doc.append(kvp(key, value));

