You’re using C*+ so you can use any C*+ library. One thing to consider is making sure you know how to compile whatever library you use for whatever platform you wish to deploy to. So if you’re trying to use something like curl on, say the iPhone or Android, then you’ll have to get help from curl-related support forums on how you can compile it for iPhone or Android.
Here’s a hint for curl on iPhone, google: ‘compile curl iphone’
I’d love to help but I’ve only ever used curl for Windows, but the best thing I can do is guide you to the right direction.