docs: copy-constructor vs copy-assignment

[El-even-11]

https://github.com/cmu-db/15445-bootcamp/blob/e2d462b821e29440da1f038e61589866c32d9dad/src/shared_ptr.cpp#L79-L80

Might use copy-constructor here?

[El-even-11]

// copy-constructed
std::shared_ptr<Point> s4 = s3;

// copy-assigned
std::shared_ptr<Point> s4;
s4 = s3;

[cscourage]

I totally agree with you too. "std::shared_ptr<Point> s4 = s3; " should be copy-construction, because it is the first time s4 appears.

"std::shared_ptr<Point> s4; // default construction s4 = s3;" // copy-assignment. and this is the situation where copy-assignment works.

[skyzh]

yep, this looks like a typo. would you please submit a pull request? thanks!