luatools: reading complex lua stack

main.cpp

int a, b, c;
std::string s;
std::vector<int> v;
lua::istack_stream(L) >> s >> lua::tab("a", a) >> lua::tab("b", b) 
   >> lua::tab("c", c) >> lua::next >> v;

script.lua

function get_complex_stack()
   return {9, 8, 7}, {a=101, b=202, c=303}, 'hello!'
end