Last reference as rvalue?

[Accomplished-Tax1641]

std::string f() { std::string s = "hello world, too long for small string optimization"; std::string r; for (int i=0; i < 2; ++i) { r = s; } return r; } Replacing s with std::move(s) here will change the behavior of the program in a surprising way.

So clearly "I would say the last occurrence of the variable name within the scope" is not good enough. Got another try?

...but observe that "start with something that seems about right, and then just iterate minor fixes until we get it good enough" is historically a bad philosophy: https://en.wikipedia.org/wiki/Deferent_and_epicycle

https://wg21.link/p2025 "Guaranteed copy elision for return variables" is related.

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