I might be bad in understanding rvalue references

[dusty summit]

why it have 3 at deleted memory?

[west thistle]

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@dusty summit

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[ebon pollen]

this is wrong

you are returning a reference to a local object, which will be destroyed by the time the function returns

[dusty summit]

yeah, i know, i just want to try it

[ebon pollen]

well then what is the question about

[dusty summit]

why it works? why 3 is exist

when i call move constructor

[ebon pollen]

when an object is destroyed it doesn't magically disappear

[hollow hound]

Undefined behavior 🙂

[native quarry]

You don't need to use an rvalue reference on a return type

T foo();
// the expression foo() is already an rvalue

[ebon pollen]

it means the memory it occupies can be overwritten at any time, because it's marked as free

3 just hasn't been overwritten yet

[native quarry]

T&& foo() { return T{}; } returns a dangling reference to the temporary you create

[hollow hound]

Also, you don't want to move out of a function like I saw in getA2()

[ebon pollen]

tl;dr the fact that it "works" is luck and you shouldn't rely on it

[native quarry]

Emphasis on the "works", it really doesn't work.

[dusty summit]

alright, thx)

i was just intrested in it

!solved

[west thistle]

Thank you and let us know if you have any more questions!

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[ebon pollen]

you can safely extend the lifetime of a temporary by binding to a const T& or T&&

but you should never return a reference to a local variable

[dusty summit]

ok