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Destructuring pt2 - confusion about temporary variables created in match statements #85

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davereikher opened this issue Jul 24, 2019 · 0 comments

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@davereikher
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In Destructuring pt2, in the second code snippet, regarding the first option of the match statement, it says

"...in the first approach we dereference x to a temporary variable with type Enum1 (which copies the value in x)...".

Enum1 has copy semantics, so it makes sense that *x (the value in x) is copied into a temp variable. From that I conclude that if there is a match statement on a dereference of an object with copy semantics, a temporary variable is created and the value of *x is copied into it. So far so good.

However, in the third code snippet, option 1 of the match statement, where the value of x (now of type Enum2) has move semantics, shouldn't the same hold true, but this time, with a move operation, making this scenario illegal? That is, when creating a match statement on a dereference of an object with move semantics, it should, following the same logic, result in a temporary variable into which *x would be moved? Or does that not apply in case of object with move semantics? That is, if you have a match statements on a dereference of an object with move semantics, no temporary variable is created?

I don't know the answer as I'm just starting out with Rust and it gets me confused. I think this point should be clarified.

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