9231ceb6dd
This small commit stabilizes the `Error` trait as-is, except that `Send` and `Debug` are added as constraints. The `Send` constraint is because most uses of `Error` will be for trait objects, and by default we would like these objects to be transferrable between threads. The `Debug` constraint is to ensure that e.g. `Box<Error>` is `Debug`, and because types that implement `Display` should certainly implement `Debug` in any case. In the near future we expect to add `Any`-like downcasting features to `Error`, but this is waiting on some additional mechanisms (`Reflect`). It will be added before 1.0 via default methods. [breaking-change]
37 lines
1.0 KiB
Rust
37 lines
1.0 KiB
Rust
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! Error handling utilities. WIP.
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use std::error::Error;
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use std::fmt;
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pub type CliError = Box<Error + 'static>;
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pub type CliResult<T> = Result<T, CliError>;
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pub type CommandError = Box<Error + 'static>;
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pub type CommandResult<T> = Result<T, CommandError>;
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pub fn err(s: &str) -> CliError {
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#[derive(Debug)]
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struct E(String);
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impl Error for E {
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fn description(&self) -> &str { &self.0 }
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}
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impl fmt::Display for E {
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fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
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self.0.fmt(f)
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}
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}
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Box::new(E(s.to_string()))
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}
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