Add another implementation example to Debug trait #92322
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Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @dtolnay (or someone else) soon. Please see the contribution instructions for more information. |
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library/core/src/fmt/mod.rs
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| @@ -570,8 +570,23 @@ impl Display for Arguments<'_> { | |||
| /// There are a number of helper methods on the [`Formatter`] struct to help you with manual | |||
| /// implementations, such as [`debug_struct`]. | |||
| /// | |||
| /// `Debug` implementations using either `derive` or the debug builder API | |||
| /// on [`Formatter`] support pretty-printing using the alternate flag: `{:#?}`. | |||
| /// For simple cases, it's also possible to implement `Debug` using the [`write!`] macro: | |||
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Simple vs non-simple isn't necessarily the right distinction to draw here. Standard vs non-standard is probably more like it. In other words types that do not wish to use the standard suite of debug representations provided by the Formatter trait (debug_struct, debug_tuple, debut_list, debug_set, debug_map) can do something totally custom by manually writing an arbitrary representation to the Formatter.
library/core/src/fmt/mod.rs
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| /// `Debug` implementations that have been created automatically by `derive` or implemented | ||
| /// manually using a [`Formatter`] can be used by pretty-printing with the alternate flag: `{:#?}`. |
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I feel like this sentence was more meaningful the way it was prior to the PR. All Debug implementations use a Formatter because that's dictated by the trait signature, and generally speaking all Debug implementations are either derived1 or manually implemented. So it's no longer clear what set of implementations is not covered by the description "created automatically by derive or implemented manually using a Formatter".
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library/core/src/fmt/mod.rs
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| /// # } | ||
| /// | ||
| /// impl fmt::Debug for Point { | ||
| /// fn fmt(&self, f: &mut fmt::Formatter <'_>) -> fmt::Result { |
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| /// fn fmt(&self, f: &mut fmt::Formatter <'_>) -> fmt::Result { | |
| /// fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
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@bors r+ rollup |
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📌 Commit 4df1a55 has been approved by |
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…, r=dtolnay Add another implementation example to Debug trait As per the discussion in: rust-lang#92276
…, r=dtolnay Add another implementation example to Debug trait As per the discussion in: rust-lang#92276
…askrgr Rollup of 7 pull requests Successful merges: - rust-lang#92182 (Label more build steps) - rust-lang#92188 (rustdoc: Clean up NestedAttributesExt trait/implementation) - rust-lang#92322 (Add another implementation example to Debug trait) - rust-lang#92448 (Set font size proportional to user's font size) - rust-lang#92517 (Explicitly pass `PATH` to the Windows exe resolver) - rust-lang#92545 (Extract init_env_logger to crate) - rust-lang#92579 (update Miri) Failed merges: r? `@ghost` `@rustbot` modify labels: rollup
As per the discussion in: #92276