# Struct failure::Backtrace [−] [src]

    pub struct Backtrace { /* fields omitted */ }

A `Backtrace`.

This is an opaque wrapper around the backtrace provided by libbacktrace. A variety of optimizations have been performed to avoid unnecessary or ill-advised work:

- If this crate is compiled in `no_std` compatible mode, `Backtrace` is an empty struct, and will be completely compiled away.
- If this crate is run without the `RUST_BACKTRACE` environmental variable enabled, the backtrace will not be generated at runtime.
- Even if a backtrace is generated, the most expensive part of generating a backtrace is symbol resolution. This backtrace does not perform symbol resolution until it is actually read (e.g. by printing it). If the Backtrace is never used for anything, symbols never get resolved.

Even with these optimizations, including a backtrace in your failure may not be appropriate to your use case. You are not required to put a backtrace in a custom `Fail` type.

## Methods

### `impl Backtrace`
[src]

#### `pub fn new() -> Backtrace`
[src]

Constructs a new backtrace. This will only create a real backtrace if the crate is compiled in std mode and the `RUST_BACKTRACE` environmental variable is activated.

## Trait Implementations

### `impl Default for Backtrace`
[src]

#### `fn default() -> Backtrace`
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Returns the "default value" for a type. Read more

### `impl Debug for Backtrace`
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#### `fn fmt(&self, f: &mut Formatter) -> Result`
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Formats the value using the given formatter. Read more

### `impl Display for Backtrace`
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#### `fn fmt(&self, f: &mut Formatter) -> Result`
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Formats the value using the given formatter. Read more

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