What is the type of the dereferenced .items iterator?

[gantonopoulos]

I have the following json which I think maps to a std::map. So I try to iterato over it using std::for_each
but I cannot figure out the correct type of the dereferenced .items iterator, so as to put it as an input argument to my unary function (code below does not compile). What would that be?

`
json json_string = "{"A": {\n"
" "code": "0x00024182",\n"
" }\n"
" },\n"
" "B": {\n"
" "code": "0x00024A01",\n"
" }\n"
" }}"_json;

std::for_each(json_string.items().begin(),json_string.items().end(),[](std::pair<const json,json>& arg)
{
    std::cout << arg.first.get<std::string>() << ":" << arg.second.get<std::string>() << "\n";
});`

[nlohmann]

See #2452

[gantonopoulos]

I really need read Cukic's book.

[gregmarr]

@gantonopoulos If you are using at least C++14, you can use auto arguments in your lambda.

std::for_each(json_string.items().begin(),json_string.items().end(),[](auto const& arg)
{
    std::cout << arg.first.get<std::string>() << ":" << arg.second.get<std::string>() << "\n";
});`

[gantonopoulos]

I tried that as well but unfortunately we are using C++11.