Sometimes you may need information that is not directly available in the event callback object.

To handle this DPP maintains a cache of commonly used data for you.

Note: As of August 30th, 2022, Discord made Guild Members a privileged intent. You must have GUILD_MEMBERS intent enabled for your app from discord developers portal to be able to look for members in cache.

Below is an example showing how to get a user from the cache

 #include <dpp/dpp.h>
 
int main() {
    /* Create bot */
    dpp::cluster bot("token", dpp::i_default_intents | dpp::i_guild_members);
 
    bot.on_log(dpp::utility::cout_logger());
 
    /* This event is fired when someone removes their reaction from a message */
    bot.on_message_reaction_remove([&bot](const dpp::message_reaction_remove_t& event) {
        /* Find the user in the cache using his discord id */
        dpp::user* reacting_user = dpp::find_user(event.reacting_user_id);
 
        /* If user not found in cache, log and return */
        if (!reacting_user) {
            bot.log(dpp::ll_info, "User with the id " + std::to_string(event.reacting_user_id) + " was not found.");
            return;
        }
 
        bot.log(dpp::ll_info, reacting_user->format_username() + " removed his reaction.");
    });
 
    bot.start(dpp::st_wait);
 
    return 0;
}

DPP caches more than just users, which you can get using the below-mentioned functions:

	#include <dpp/dpp.h>

	int main() {
	/* Create bot */
	dpp::cluster bot("token", dpp::i_default_intents \| dpp::i_guild_members);

	bot.on_log(dpp::utility::cout_logger());

	/* This event is fired when someone removes their reaction from a message */
	bot.on_message_reaction_remove([&bot](const dpp::message_reaction_remove_t& event) {
	/* Find the user in the cache using his discord id */
	dpp::user* reacting_user = dpp::find_user(event.reacting_user_id);

	/* If user not found in cache, log and return */
	if (!reacting_user) {
	bot.log(dpp::ll_info, "User with the id " + std::to_string(event.reacting_user_id) + " was not found.");
	return;
	}

	bot.log(dpp::ll_info, reacting_user->format_username() + " removed his reaction.");
	});

	bot.start(dpp::st_wait);

	return 0;
	}