Crate whaterror

Source
Expand description

There is nothing at all in your return type, useful or otherwise.

Proc macro attribute for a more customizable alternative to the standard library’s Termination trait.

As a simple example, this replicates the standard behavior for fn main() returning Result<T, E>:

ⓘ
use whaterror::whaterror;

#[whaterror(|err| eprintln!("Error: {:#?}", err))]
fn main() -> Result<(), Error> {
    Err(Error::Failed)
}

If your handler returns, whaterror will automatically exit with code 1 (or panic if inside a test).

This also works for Option<T>:

ⓘ
use whaterror::whaterror;

#[whaterror(|| eprintln!("returned None"))]
fn main() -> Option<()> {
    None
}

The || isn’t necessary in this case, since there are no arguments:

use whaterror::whaterror;

#[whaterror(unreachable!())]
fn main() -> Option<()> {
    Some(())
}

This works for non-() types just like you would expect. Non-main functions are technically allowed, but currently have very strict limitations. These limitations are planned to be lifted in the future.

Modules§

  • option
    Implementations for Option<T>.
  • result
    Implementations for Result<T, E>.

Traits§

  • FatalError
    Represents an error to be handled by whaterror.
  • Termination
    Represents a return value to be handled by whaterror.

Attribute Macros§