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#[cfg(feature = "std")]
use std::error::Error;
#[cfg(not(feature = "std"))]
use std::fmt::Display;
use std::path::PathBuf;
use err_derive::Error;
#[derive(Debug, Error)]
pub enum FormatError {
#[error(
display = "invalid header (expected: {:?}, got: {:?})",
expected,
found
)]
InvalidHeader { expected: String, found: String },
#[error(display = "missing attribute: {:?}", _0)]
MissingAttribute(String),
}
#[derive(Debug, Error)]
pub enum LoadingError {
#[error(display = "could not decode file")]
FormatError(#[error(source)] FormatError),
#[error(display = "could not find file: {:?}", path)]
NotFound { path: PathBuf },
}
fn main() {
let my_error: LoadingError = FormatError::MissingAttribute("some_attr".to_owned()).into();
print_error(&my_error);
}
#[cfg(feature = "std")]
fn print_error(e: &dyn Error) {
eprintln!("error: {}", e);
let mut cause = e.source();
while let Some(e) = cause {
eprintln!("caused by: {}", e);
cause = e.source();
}
}
#[cfg(not(feature = "std"))]
fn print_error(e: &dyn Display) {
eprintln!("error: {}", e);
}
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