How can I make asynchronous requests using the C++ REST SDK?

How can I make asynchronous requests using the C++ REST SDK?

You can use the http_client class to make asynchronous requests. First, create an instance of http_client, then call methods like request with a callback.

Can you show me a code example?

Sure! Here's a simple example:

#include <cpprest/http_client.h>

using namespace web;
using namespace web::http;
using namespace web::http::client;

int main() {
    http_client client(U("http://example.com"));
    client.request(methods::GET).then([](http_response response) {
        if (response.status_code() == status_codes::OK) {
            return response.extract_string();
        }
        return pplx::task_from_result(U(""));
    }).then([](utility::string_t body) {
        std::wcout << body << std::endl;
    }).wait();
    return 0;
}

This code makes an async GET request and prints the response.

What if I want to handle errors?

You can add error handling by chaining another then or using catch to handle exceptions. Here's an example:

client.request(methods::GET).then([](http_response response) {
    if (response.status_code() == status_codes::OK) {
        return response.extract_string();
    }
    throw std::runtime_error("Request failed");
}).then([](utility::string_t body) {
    std::wcout << body << std::endl;
}).then([]() {
    std::wcout << "Request completed successfully." << std::endl;
}).wait();

This way, you can catch errors and handle them appropriately.

Thanks! This is really helpful.

You're welcome! If you have any more questions about C++ or the REST SDK, feel free to ask!