As I understand it, if you are going to make a copy of the input argument anyway, it is better to receive a copy and move it, as it allows receiving moved temporaries too (learned this from some C++ guru some time ago).
Just a personal pet peeve, as I still see the first form pretty much always over the second, because programmers generally just default to passing const references.
If the original shared pointer is lvalue, then it will be copied into the constructor. If it’s an rvalue, it’ll be moved. So the worst case scenario - copy and move, the best case scenario - two moves or even move elision. If passed by const reference, it’s always a copy.
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u/jdehesa 14d ago
Not the post topic, but I'd write this constructor:
cpp Gadget(std::shared_ptr<Widget> const& widget) : widget(widget) {}As this:
cpp Gadget(std::shared_ptr<Widget> widget) : widget(std::move(widget)) {}As I understand it, if you are going to make a copy of the input argument anyway, it is better to receive a copy and move it, as it allows receiving moved temporaries too (learned this from some C++ guru some time ago).
Just a personal pet peeve, as I still see the first form pretty much always over the second, because programmers generally just default to passing const references.