nordic-dev.net/rust
nordic-dev.net/rust
2
0
Fork 0
mirror of https://github.com/rust-lang/rust.git synced 2025-04-28 02:57:37 +00:00
Code Issues Packages Projects Releases Wiki Activity

Rollup merge of #53523 - phungleson:fix-impl-from-for-std-error, r=GuillaumeGomez

Browse Source 
Add doc for impl From for Std Error

As part of issue #51430 (cc @skade).

I am not sure if it is going to a correct direction so put up here so that people can comment.
This commit is contained in:
Pietro Albini 2018-10-04 12:20:05 +02:00 committed by GitHub
commit 1dbc8b0d4b
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 141 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

141
src/libstd/error.rs
View File

@ -217,6 +217,35 @@ pub trait Error: Debug + Display {
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, E: Error + 'a> From<E> for Box<dyn Error + 'a> {
/// Converts a type of [`Error`] into a box of dyn [`Error`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::fmt;
/// use std::mem;
///
/// #[derive(Debug)]
/// struct AnError;
///
/// impl fmt::Display for AnError {
/// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
/// write!(f , "An error")
/// }
/// }
///
/// impl Error for AnError {
/// fn description(&self) -> &str {
/// "Description of an error"
/// }
/// }
///
/// let an_error = AnError;
/// assert!(0 == mem::size_of_val(&an_error));
/// let a_boxed_error = Box::<Error>::from(an_error);
/// assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: E) -> Box<dyn Error + 'a> {
Box::new(err)
}
@ -224,6 +253,41 @@ impl<'a, E: Error + 'a> From<E> for Box<dyn Error + 'a> {
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, E: Error + Send + Sync + 'a> From<E> for Box<dyn Error + Send + Sync + 'a> {
/// Converts a type of [`Error`] + [`Send`] + [`Sync`] into a box of dyn [`Error`] +
/// [`Send`] + [`Sync`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::fmt;
/// use std::mem;
///
/// #[derive(Debug)]
/// struct AnError;
///
/// impl fmt::Display for AnError {
/// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
/// write!(f , "An error")
/// }
/// }
///
/// impl Error for AnError {
/// fn description(&self) -> &str {
/// "Description of an error"
/// }
/// }
///
/// unsafe impl Send for AnError {}
///
/// unsafe impl Sync for AnError {}
///
/// let an_error = AnError;
/// assert!(0 == mem::size_of_val(&an_error));
/// let a_boxed_error = Box::<Error + Send + Sync>::from(an_error);
/// assert!(
/// mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: E) -> Box<dyn Error + Send + Sync + 'a> {
Box::new(err)
}
@ -231,6 +295,19 @@ impl<'a, E: Error + Send + Sync + 'a> From<E> for Box<dyn Error + Send + Sync +
#[stable(feature = "rust1", since = "1.0.0")]
impl From<String> for Box<dyn Error + Send + Sync> {
/// Converts a [`String`] into a box of dyn [`Error`] + [`Send`] + [`Sync`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
///
/// let a_string_error = "a string error".to_string();
/// let a_boxed_error = Box::<Error + Send + Sync>::from(a_string_error);
/// assert!(
/// mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: String) -> Box<dyn Error + Send + Sync> {
#[derive(Debug)]
struct StringError(String);
@ -251,6 +328,18 @@ impl From<String> for Box<dyn Error + Send + Sync> {
#[stable(feature = "string_box_error", since = "1.6.0")]
impl From<String> for Box<dyn Error> {
/// Converts a [`String`] into a box of dyn [`Error`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
///
/// let a_string_error = "a string error".to_string();
/// let a_boxed_error = Box::<Error>::from(a_string_error);
/// assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(str_err: String) -> Box<dyn Error> {
let err1: Box<dyn Error + Send + Sync> = From::from(str_err);
let err2: Box<dyn Error> = err1;
@ -260,6 +349,19 @@ impl From<String> for Box<dyn Error> {
#[stable(feature = "rust1", since = "1.0.0")]
impl<'a, 'b> From<&'b str> for Box<dyn Error + Send + Sync + 'a> {
/// Converts a [`str`] into a box of dyn [`Error`] + [`Send`] + [`Sync`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
///
/// let a_str_error = "a str error";
/// let a_boxed_error = Box::<Error + Send + Sync>::from(a_str_error);
/// assert!(
/// mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: &'b str) -> Box<dyn Error + Send + Sync + 'a> {
From::from(String::from(err))
}
@ -267,6 +369,18 @@ impl<'a, 'b> From<&'b str> for Box<dyn Error + Send + Sync + 'a> {
#[stable(feature = "string_box_error", since = "1.6.0")]
impl<'a> From<&'a str> for Box<dyn Error> {
/// Converts a [`str`] into a box of dyn [`Error`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
///
/// let a_str_error = "a str error";
/// let a_boxed_error = Box::<Error>::from(a_str_error);
/// assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: &'a str) -> Box<dyn Error> {
From::from(String::from(err))
}
@ -274,6 +388,20 @@ impl<'a> From<&'a str> for Box<dyn Error> {
#[stable(feature = "cow_box_error", since = "1.22.0")]
impl<'a, 'b> From<Cow<'b, str>> for Box<dyn Error + Send + Sync + 'a> {
/// Converts a [`Cow`] into a box of dyn [`Error`] + [`Send`] + [`Sync`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
/// use std::borrow::Cow;
///
/// let a_cow_str_error = Cow::from("a str error");
/// let a_boxed_error = Box::<Error + Send + Sync>::from(a_cow_str_error);
/// assert!(
/// mem::size_of::<Box<dyn Error + Send + Sync>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: Cow<'b, str>) -> Box<dyn Error + Send + Sync + 'a> {
From::from(String::from(err))
}
@ -281,6 +409,19 @@ impl<'a, 'b> From<Cow<'b, str>> for Box<dyn Error + Send + Sync + 'a> {
#[stable(feature = "cow_box_error", since = "1.22.0")]
impl<'a> From<Cow<'a, str>> for Box<dyn Error> {
/// Converts a [`Cow`] into a box of dyn [`Error`].
///
/// # Examples
///
/// ```
/// use std::error::Error;
/// use std::mem;
/// use std::borrow::Cow;
///
/// let a_cow_str_error = Cow::from("a str error");
/// let a_boxed_error = Box::<Error>::from(a_cow_str_error);
/// assert!(mem::size_of::<Box<dyn Error>>() == mem::size_of_val(&a_boxed_error))
/// ```
fn from(err: Cow<'a, str>) -> Box<dyn Error> {
From::from(String::from(err))
}