Macro uucore::uio_error

macro_rules! uio_error {
    ($err:expr, $($args:tt)+) => { ... };
}

Shorthand to construct UIoError-instances.

This macro serves as a convenience call to quickly construct instances of UIoError. It takes:

• An instance of std::io::Error
• A format!-compatible string and
• An arbitrary number of arguments to the format string

In exactly this order. It is equivalent to the more verbose code seen in the example.

Examples

use uucore::error::UIoError;
use uucore::uio_error;

let io_err = std::io::Error::new(
    std::io::ErrorKind::PermissionDenied, "fix me please!"
);

let uio_err = UIoError::new(
    io_err.kind(),
    format!("Error code: {}", 2)
);

let other_uio_err = uio_error!(io_err, "Error code: {}", 2);

// prints "fix me please!: Permission denied"
println!("{}", uio_err);
// prints "Error code: 2: Permission denied"
println!("{}", other_uio_err);

The std::fmt::Display impl of UIoError will then ensure that an appropriate error message relating to the actual error kind of the std::io::Error is appended to whatever error message is defined in addition (as secondary argument).

If you want to show only the error message for the std::io::ErrorKind that’s contained in UIoError, pass the second argument as empty string:

use uucore::error::UIoError;
use uucore::uio_error;

let io_err = std::io::Error::new(
    std::io::ErrorKind::PermissionDenied, "fix me please!"
);

let other_uio_err = uio_error!(io_err, "");

// prints: ": Permission denied"
println!("{}", other_uio_err);