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Github tracking issue for `debug_non_exhaustive` feature · Issue #67364 · rust-l...

 3 years ago
source link: https://github.com/rust-lang/rust/issues/67364
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derekdreery commented on Dec 17, 2019 •

edited by m-ou-se

Feature gate: #![feature(debug_non_exhaustive)]

This is a tracking issue for adding the ability to add an ellipsis to the end of the Debug representation of a struct, to indicate that the struct has more fields, but that these fields are not displayable. This involves adding the finish_non_exhaustive method to DebugStruct, that produces output like

Name { field1: value1, .. }

where the .. indicate that there are more hidden fields.

Public API

// core::fmt

impl<'a, 'b: 'a> DebugStruct<'a, 'b> {
    pub fn finish_non_exhaustive(&mut self) -> fmt::Result;
}

Steps / History

  • Implementation: #66716
  • Final commenting period (FCP): #67364 (comment)
  • Stabilization PR: #83041
  • Replace .finish() by .finish_non_exhaustive() within the standard library where it makes sense.

Unresolved Questions

  • Should this method be implemented for DebugTuple and DebugMap as well?
    • I would probably say "no" since I can't think of any use cases for them. They could always be added later.

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