STL containers visualisation on Mac OS with lldb

Hi. My CMakeLists file looks like this:

cmake_minimum_required(VERSION 3.8)
project(Prog)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

set(SOURCE_FILES main.cpp)
add_executable(Prog ${SOURCE_FILES})

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++17 -stdlib=libstdc++")

I'm using Mac OS Sierra and LLDB 3.9.0. In this case I can inspect elements of STL containers in debug mode but <unordered_set> and <unordered_map> are unavailable. Also I can't use built-in function to_string(). What should I do to fix this?