697737a8b1
Make Rust pointers less magic by including metadata information in their `Debug` output. This does not break Rust stability guarantees because `Debug` output is explicitly exempted from stability: https://doc.rust-lang.org/std/fmt/trait.Debug.html#stability Co-authored-by: Lukas <26522220+lukas-code@users.noreply.github.com> Co-authored-by: Josh Stone <cuviper@gmail.com>
36 lines
825 B
Rust
36 lines
825 B
Rust
/// Collapses all unit items from an iterator into one.
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///
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/// This is more useful when combined with higher-level abstractions, like
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/// collecting to a `Result<(), E>` where you only care about errors:
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///
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/// ```
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/// use std::io::*;
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/// let data = vec![1, 2, 3, 4, 5];
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/// let res: Result<()> = data.iter()
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/// .map(|x| writeln!(stdout(), "{x}"))
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/// .collect();
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/// assert!(res.is_ok());
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/// ```
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#[stable(feature = "unit_from_iter", since = "1.23.0")]
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impl FromIterator<()> for () {
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fn from_iter<I: IntoIterator<Item = ()>>(iter: I) -> Self {
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iter.into_iter().for_each(|()| {})
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}
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}
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pub(crate) trait IsUnit {
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fn is_unit() -> bool;
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}
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impl<T: ?Sized> IsUnit for T {
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default fn is_unit() -> bool {
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false
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}
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}
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impl IsUnit for () {
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fn is_unit() -> bool {
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true
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}
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}
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