feat(move_semantics): clarify some hints
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// move_semantics1.rs
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// Make me compile! Execute `rustlings hint move_semantics1` for hints :)
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// Execute `rustlings hint move_semantics1` or use the `hint` watch subcommand for a hint.
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// I AM NOT DONE
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@ -1,6 +1,6 @@
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// move_semantics2.rs
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// Make me compile without changing line 13 or moving line 10!
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// Execute `rustlings hint move_semantics2` for hints :)
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// Execute `rustlings hint move_semantics2` or use the `hint` watch subcommand for a hint.
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// I AM NOT DONE
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15
info.toml
15
info.toml
@ -280,18 +280,21 @@ mode = "compile"
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hint = """
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So you've got the "cannot borrow immutable local variable `vec1` as mutable" error on line 13,
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right? The fix for this is going to be adding one keyword, and the addition is NOT on line 13
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where the error is."""
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where the error is.
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Also: Try accessing `vec0` after having called `fill_vec()`. See what happens!"""
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[[exercises]]
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name = "move_semantics2"
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path = "exercises/move_semantics/move_semantics2.rs"
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mode = "compile"
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hint = """
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So `vec0` is being *moved* into the function `fill_vec` when we call it on
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line 10, which means it gets dropped at the end of `fill_vec`, which means we
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can't use `vec0` again on line 13 (or anywhere else in `main` after the
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`fill_vec` call for that matter). We could fix this in a few ways, try them
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all!
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So, `vec0` is passed into the `fill_vec` function as an argument. In Rust,
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when an argument is passed to a function and it's not explicitly returned,
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you can't use the original variable anymore. We call this "moving" a variable.
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Variables that are moved into a function (or block scope) and aren't explicitly
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returned get "dropped" at the end of that function. This is also what happens here.
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There's a few ways to fix this, try them all if you want:
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1. Make another, separate version of the data that's in `vec0` and pass that
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to `fill_vec` instead.
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2. Make `fill_vec` borrow its argument instead of taking ownership of it,
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