Beef up Copy documentation #21261
Beef up Copy documentation #21261
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r? @pcwalton (rust_highfive has picked a reviewer for you, use r? to override) |
| /// | ||
| /// ``` | ||
| /// struct MyStruct; | ||
| /// impl Copy for MyStruct; |
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I think this impl will need braces after it
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The tests do pass...
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Weird...
struct Foo;
impl Copy for Foo;foo.rs:3:18: 3:19 error: expected one of `(`, `+`, `::`, or `{`, found `;`
foo.rs:3 impl Copy for Foo;
^
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r=me with doc fix |
| /// | ||
| /// ``` | ||
| /// struct MyStruct; | ||
| /// impl Copy for MyStruct {}; |
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I think this semicolon will still need to be removed :(
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I fixed the semicolon. @kmcallister what do you think is the right full explanation for |
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Okay, I think this is good now. One more review? |
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Looks great! |
| /// ## When should my type be `Copy`? | ||
| /// | ||
| /// Generally speaking, if your type _can_ implement `Copy`, it should. There's one important thing | ||
| /// to consider though: if you think your type may _not_ be able to implement `Copy` in the future, |
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Might also want to mention that it is sometimes useful to have types with no Drop impl but which shouldn't be Copy because they represent some kind of unique logical token or otherwise require more than just a bitwise copy to semantically copy them.
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I've found success phrasing copy vs. move in terms of using values by-value, and "byte copies" and "semantic copies" and generally trying to divorce the two uses of the word "copy" because this overloading confuses people a lot.
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Beef up Copy documentation Reviewed-by: alexcrichton
Beef up Copy documentation Reviewed-by: alexcrichton
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Doing this manually as part of #21300 |
Fixes #21249
Fixes #11540
/cc @alexcrichton , @kmcallister