//! [![github]](https://github.com/dtolnay/thiserror) [![crates-io]](https://crates.io/crates/thiserror) [![docs-rs]](https://docs.rs/thiserror)
//!
//! [github]: https://img.shields.io/badge/github-8da0cb?style=for-the-badge&labelColor=555555&logo=github
//! [crates-io]: https://img.shields.io/badge/crates.io-fc8d62?style=for-the-badge&labelColor=555555&logo=rust
//! [docs-rs]: https://img.shields.io/badge/docs.rs-66c2a5?style=for-the-badge&labelColor=555555&logoColor=white&logo=data:image/svg+xml;base64,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
//!
//! <br>
//!
//! This library provides a convenient derive macro for the standard library's
//! [`std::error::Error`] trait.
//!
//! [`std::error::Error`]: https://doc.rust-lang.org/std/error/trait.Error.html
//!
//! <br>
//!
//! # Example
//!
//! ```rust
//! # use std::io;
//! use thiserror::Error;
//!
//! #[derive(Error, Debug)]
//! pub enum DataStoreError {
//! #[error("data store disconnected")]
//! Disconnect(#[from] io::Error),
//! #[error("the data for key `{0}` is not available")]
//! Redaction(String),
//! #[error("invalid header (expected {expected:?}, found {found:?})")]
//! InvalidHeader {
//! expected: String,
//! found: String,
//! },
//! #[error("unknown data store error")]
//! Unknown,
//! }
//! ```
//!
//! <br>
//!
//! # Details
//!
//! - Thiserror deliberately does not appear in your public API. You get the
//! same thing as if you had written an implementation of `std::error::Error`
//! by hand, and switching from handwritten impls to thiserror or vice versa
//! is not a breaking change.
//!
//! - Errors may be enums, structs with named fields, tuple structs, or unit
//! structs.
//!
//! - A `Display` impl is generated for your error if you provide
//! `#[error("...")]` messages on the struct or each variant of your enum, as
//! shown above in the example.
//!
//! The messages support a shorthand for interpolating fields from the error.
//!
//! - `#[error("{var}")]` ⟶ `write!("{}", self.var)`
//! - `#[error("{0}")]` ⟶ `write!("{}", self.0)`
//! - `#[error("{var:?}")]` ⟶ `write!("{:?}", self.var)`
//! - `#[error("{0:?}")]` ⟶ `write!("{:?}", self.0)`
//!
//! These shorthands can be used together with any additional format args,
//! which may be arbitrary expressions. For example:
//!
//! ```rust
//! # use thiserror::Error;
//! #
//! #[derive(Error, Debug)]
//! pub enum Error {
//! #[error("invalid rdo_lookahead_frames {0} (expected < {})", i32::max_value())]
//! InvalidLookahead(u32),
//! }
//! ```
//!
//! If one of the additional expression arguments needs to refer to a field of
//! the struct or enum, then refer to named fields as `.var` and tuple fields
//! as `.0`.
//!
//! ```rust
//! # use thiserror::Error;
//! #
//! # fn first_char(s: &String) -> char {
//! # s.chars().next().unwrap()
//! # }
//! #
//! # #[derive(Debug)]
//! # struct Limits {
//! # lo: usize,
//! # hi: usize,
//! # }
//! #
//! #[derive(Error, Debug)]
//! pub enum Error {
//! #[error("first letter must be lowercase but was {:?}", first_char(.0))]
//! WrongCase(String),
//! #[error("invalid index {idx}, expected at least {} and at most {}", .limits.lo, .limits.hi)]
//! OutOfBounds { idx: usize, limits: Limits },
//! }
//! ```
//!
//! - A `From` impl is generated for each variant containing a `#[from]`
//! attribute.
//!
//! Note that the variant must not contain any other fields beyond the source
//! error and possibly a backtrace. A backtrace is captured from within the
//! `From` impl if there is a field for it.
//!
//! ```rust
//! # const IGNORE: &str = stringify! {
//! #[derive(Error, Debug)]
//! pub enum MyError {
//! Io {
//! #[from]
//! source: io::Error,
//! backtrace: Backtrace,
//! },
//! }
//! # };
//! ```
//!
//! - The Error trait's `source()` method is implemented to return whichever
//! field has a `#[source]` attribute or is named `source`, if any. This is
//! for identifying the underlying lower level error that caused your error.
//!
//! The `#[from]` attribute always implies that the same field is `#[source]`,
//! so you don't ever need to specify both attributes.
//!
//! Any error type that implements `std::error::Error` or dereferences to `dyn
//! std::error::Error` will work as a source.
//!
//! ```rust
//! # use std::fmt::{self, Display};
//! # use thiserror::Error;
//! #
//! #[derive(Error, Debug)]
//! pub struct MyError {
//! msg: String,
//! #[source] // optional if field name is `source`
//! source: anyhow::Error,
//! }
//! #
//! # impl Display for MyError {
//! # fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
//! # unimplemented!()
//! # }
//! # }
//! ```
//!
//! - The Error trait's `backtrace()` method is implemented to return whichever
//! field has a type named `Backtrace`, if any.
//!
//! ```rust
//! # const IGNORE: &str = stringify! {
//! use std::backtrace::Backtrace;
//!
//! #[derive(Error, Debug)]
//! pub struct MyError {
//! msg: String,
//! backtrace: Backtrace, // automatically detected
//! }
//! # };
//! ```
//!
//! - Errors may use `error(transparent)` to forward the source and Display
//! methods straight through to an underlying error without adding an
//! additional message. This would be appropriate for enums that need an
//! "anything else" variant.
//!
//! ```
//! # use thiserror::Error;
//! #
//! #[derive(Error, Debug)]
//! pub enum MyError {
//! # /*
//! ...
//! # */
//!
//! #[error(transparent)]
//! Other(#[from] anyhow::Error), // source and Display delegate to anyhow::Error
//! }
//! ```
//!
//! - See also the [`anyhow`] library for a convenient single error type to use
//! in application code.
//!
//! [`anyhow`]: https://github.com/dtolnay/anyhow
mod aserror;
mod display;
pub use thiserror_impl::*;
// Not public API.
#[doc(hidden)]
pub mod private {
pub use crate::aserror::AsDynError;
pub use crate::display::{DisplayAsDisplay, PathAsDisplay};
}