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use crate::util::AnyValueId;
/// Violation of [`ArgMatches`][crate::ArgMatches] assumptions
#[derive(Clone, Debug)]
#[allow(missing_copy_implementations)] // We might add non-Copy types in the future
#[non_exhaustive]
pub enum MatchesError {
/// Failed to downcast `AnyValue` to the specified type
#[non_exhaustive]
Downcast {
/// Type for value stored in [`ArgMatches`][crate::ArgMatches]
actual: AnyValueId,
/// The target type to downcast to
expected: AnyValueId,
},
/// Argument not defined in [`Command`][crate::Command]
#[non_exhaustive]
UnknownArgument {
// Missing `id` but blocked on a public id type which will hopefully come with `unstable-v4`
},
}
impl MatchesError {
#[cfg_attr(debug_assertions, track_caller)]
pub(crate) fn unwrap<T>(id: &str, r: Result<T, MatchesError>) -> T {
let err = match r {
Ok(t) => {
return t;
}
Err(err) => err,
};
panic!("Mismatch between definition and access of `{id}`. {err}",)
}
}
impl std::error::Error for MatchesError {}
impl std::fmt::Display for MatchesError {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
Self::Downcast { actual, expected } => {
writeln!(
f,
"Could not downcast to {expected:?}, need to downcast to {actual:?}"
)
}
Self::UnknownArgument {} => {
writeln!(f, "Unknown argument or group id. Make sure you are using the argument id and not the short or long flags")
}
}
}
}
#[test]
fn check_auto_traits() {
static_assertions::assert_impl_all!(
MatchesError: Send,
Sync,
std::panic::RefUnwindSafe,
std::panic::UnwindSafe,
Unpin
);
}