improve documentation for Fn* traits
#35810
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| /// | ||
| /// The `Fn` trait governs the invocation operator `()`. Closures automatically | ||
| /// implement this trait, which allows them to be invoked. Note, however, that | ||
| /// `Fn` takes an immutable reference to the argument. To take an immutable |
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I think you want to write "to take an mutable"
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I do indeed. Thank you! I'll go ahead and refactor these docs a bit now.
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I've added some more documentation, more for form then contact at this point because I don't quite understand these traits yet. |
| @@ -64,6 +64,50 @@ | |||
| //! | |||
| //! See the documentation for each trait for a minimum implementation that | |||
| //! prints something to the screen. | |||
| //! | |||
| //! The `Fn`, `FnMut`, and `FnOnce` traits are implemented by types that can be | |||
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these should link to the traits
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This is now approaching a serious attempt at contribution. :P |
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Nice! Seems good to me but I'll let @steveklabnik handles it. |
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Actually, I believe my |
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Okay, fixed. |
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☔ The latest upstream changes (presumably #35857) made this pull request unmergeable. Please resolve the merge conflicts. |
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| //! func(1) | ||
| //! } | ||
| //! | ||
| //! let double = |x| x + x; |
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Perhaps x * 2? I associate doubling with multiplication (though the two are clearly equivalent).
I can think of a few things we may want to accomplish with the documentation of the `Fn`, `FnMut`, and `FnOnce` traits: - the relationship between these traits and the closures that implement them - examples of non-closure implementations - the relationship between these traits and Rust's ownership semantics add module-level documentation for `Fn*` traits Describe how `Fn*` traits, closure types, and ownership semantics are linked, and provide examples of higher-level functions that take `Fn*`s. more examples for `Fn*` traits create correct (though not yet elegant) examples for `FnMut` and `FnOnce` add trait links to module-level documentation third time's a charm! argument -> capture for trait documentation This wording will need to be supported with better examples for capturing eventually. correct `FnOnce` example I also fixed some of the trait wording here to make the concept of capturing clearer; though that still needs more work. replace `x + x` with `x * 2` for `fn double`
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@bors: r+ rollup thanks a lot! |
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📌 Commit 67b9cd3 has been approved by |
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⌛ Testing commit 67b9cd3 with merge 78f057b... |
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💔 Test failed - auto-mac-64-opt-rustbuild |
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@bors retry |
…steveklabnik improve documentation for `Fn*` traits This PR is not yet a serious attempt at contribution. Rather, I'm opening this for discussion. I can think of a few things we may want to accomplish with the documentation of the `Fn`, `FnMut`, and `FnOnce` traits: - the relationship between these traits and the closures that implement them - examples of non-closure implementations - the relationship between these traits and Rust's ownership semantics
This PR is not yet a serious attempt at contribution. Rather, I'm opening this for discussion. I can think of a few things we may want to accomplish with the documentation of the
Fn,FnMut, andFnOncetraits: