:sig
bool mysql_connected(MySQL* m)

:params
m : pointer returned by mysql_connect()
return value : true only when the wrapper owns a live server connection

:see
>mysql

:content
Tests whether a MySQL wrapper has a usable server connection. `mysql_connect()` retains a failed wrapper so that callers can retrieve its diagnostic through `mysql_error()`; this helper distinguishes that state from a live handle without consuming the diagnostic.

:example
MySQL* db = mysql_connect();
if(!mysql_connected(db))
{
    print("database unavailable: ", mysql_error(db), "\n");
}
else print("database connected\n");
if(db != 0) mysql_disconnect(db);
