Thanks!
Instead of looking far into the future, let's look at the present moment or last recorded year. China was already far bigger than
any country on this planet in terms of
patent filings (31% of world total, 2014),
industrial design filings (49% of world total, 2014),
industrial GDP ($4.422 trillion, 2014),
manufacturing VA ($3.713 trillion, 2014),
merchandise exports to rest-of-the-world ($2.343 trillion, 2014),
high-tech exports to rest-of-the-world ($560 billion, 2013),
trade surpluses with rest-of-the-world ($382 billion in 2014; my estimate for 2015 is $600 billion),
gross domestic savings,
financial reserves,
sovereign welfare fund, and many more indicators. China mainland alone is the second largest
creditor nation (the opposite of debtor nation) after Japan, Greater China (+HK +TW) combined number one largest.
However it's not about overtaking anything, but to make China as well as partnering countries more prosperous, especially friends like Pakistan. All the best bro!
Data sources: