Struct Report

pub struct Report<'a>(pub &'a dyn Error);

A wrapper around an error that provides a cleaned up error trace for display and debug formatting.

Constructed using AsReport::as_report.

Formatting

The report can be formatted using fmt::Display or fmt::Debug, which differs based on the alternate flag (#).

• Without the alternate flag, the error is formatted in a compact way:

  Outer error text: Middle error text: Inner error text

• With the alternate flag, the error is formatted in a multi-line format, which is more readable:

  Outer error text
  
  Caused by these errors (recent errors listed first):
    1. Middle error text
    2. Inner error text

• Additionally, fmt::Debug provide backtraces if available.

Error source cleaning

It’s common for errors with a source to have a Display implementation that includes their source text as well:

Outer error text: Middle error text: Inner error text

This works for smaller errors without much detail, but can be annoying when trying to format the error in a more structured way, such as line-by-line:

1. Outer error text: Middle error text: Inner error text
2. Middle error text: Inner error text
3. Inner error text

This iterator compares each pair of errors in the source chain, removing the source error’s text from the containing error’s text:

1. Outer error text
2. Middle error text
3. Inner error text

Tuple Fields

0: &'a dyn Error

Trait Implementations

impl<'a> Debug for Report<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'a> Display for Report<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.