1//! Definitions used in derived implementations of [`core::ops::Add`]-like traits.
2
3use core::fmt;
4
5use crate::UnitError;
6
7/// Error returned by the derived implementations when an arithmetic or logic
8/// operation is invoked on mismatched enum variants.
9#[derive(Clone, Copy, Debug)]
10pub struct WrongVariantError {
11 operation_name: &'static str,
12}
13
14impl WrongVariantError {
15 #[doc(hidden)]
16 #[must_use]
17 #[inline]
18 pub const fn new(operation_name: &'static str) -> Self {
19 Self { operation_name }
20 }
21}
22
23impl fmt::Display for WrongVariantError {
24 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
25 write!(
26 f,
27 "Trying to {}() mismatched enum variants",
28 self.operation_name,
29 )
30 }
31}
32
33#[cfg(feature = "std")]
34impl std::error::Error for WrongVariantError {}
35
36/// Possible errors returned by the derived implementations of binary
37/// arithmetic or logic operations.
38#[derive(Clone, Copy, Debug)]
39pub enum BinaryError {
40 /// Operation is attempted between mismatched enum variants.
41 Mismatch(WrongVariantError),
42
43 /// Operation is attempted on unit-like enum variants.
44 Unit(UnitError),
45}
46
47impl fmt::Display for BinaryError {
48 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
49 match self {
50 Self::Mismatch(e: &WrongVariantError) => write!(f, "{e}"),
51 Self::Unit(e: &UnitError) => write!(f, "{e}"),
52 }
53 }
54}
55
56#[cfg(feature = "std")]
57impl std::error::Error for BinaryError {
58 fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
59 match self {
60 Self::Mismatch(e: &WrongVariantError) => e.source(),
61 Self::Unit(e: &UnitError) => e.source(),
62 }
63 }
64}
65