Bump to 0.2.4 (#43)

* Bump to 0.2.4

* Update readme

Author: Manishearth

CHANGELOG.md

@@ -8,6 +8,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased] - ReleaseDate
 
+# [0.2.4] - 2022-05-02
+
+## Added
+- Updated `syn` dependency to 2.0
+- Support for empty enums
+- Implicitly require fmt::Display on all type parameters unless overridden
+
+## Changed
+- Bumped MSRV to 1.56
+
 # [0.2.3] - 2021-07-16
 ## Added
 - Added `#[displaydoc("..")]` attribute for overriding a doc comment
@@ -32,7 +42,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   lines are needed.
 
 <!-- next-url -->
-[Unreleased]: https://github.com/yaahc/displaydoc/compare/v0.2.3...HEAD
+[Unreleased]: https://github.com/yaahc/displaydoc/compare/v0.2.4...HEAD
+[0.2.4]: https://github.com/yaahc/displaydoc/compare/v0.2.3...v0.2.4
 [0.2.3]: https://github.com/yaahc/displaydoc/compare/v0.2.2...v0.2.3
 [0.2.2]: https://github.com/yaahc/displaydoc/compare/v0.2.1...v0.2.2
 [0.2.1]: https://github.com/yaahc/displaydoc/compare/v0.2.0...v0.2.1

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "displaydoc"
-version = "0.2.3"
+version = "0.2.4"
 authors = ["Jane Lusby <[email protected]>"]
 edition = "2018"
 license = "MIT OR Apache-2.0"

README.md

@@ -20,6 +20,8 @@ displaydoc = "0.2"
 
 ### Example
 
+*Demonstration alongside the [`Error`][std::error::Error] derive macro from [`thiserror`](https://docs.rs/thiserror/1.0.25/thiserror/index.html),
+to propagate source locations from [`io::Error`][std::io::Error] with the `#[source]` attribute:*
 ```rust
 use std::io;
 use displaydoc::Display;
@@ -39,22 +41,36 @@ pub enum DataStoreError {
     /// unknown data store error
     Unknown,
 }
+
+let error = DataStoreError::Redaction("CLASSIFIED CONTENT".to_string());
+assert!("the data for key `CLASSIFIED CONTENT` is not available" == &format!("{}", error));
 ```
+*Note that although [`io::Error`][std::io::Error] implements `Display`, we do not add it to the
+generated message for `DataStoreError::Disconnect`, since it is already made available via
+`#[source]`. See further context on avoiding duplication in error reports at the rust blog
+[here](https://github.com/yaahc/blog.rust-lang.org/blob/master/posts/inside-rust/2021-05-15-What-the-error-handling-project-group-is-working-towards.md#duplicate-information-issue).*
 
 <br>
 
 ### Details
 
-- A `Display` impl is generated for your type if you provide doc comment
-  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.
-
+- A `fmt::Display` impl is generated for your enum if you provide
+  a docstring comment on each variant as shown above in the example. The
+  `Display` derive macro supports a shorthand for interpolating fields from
+  the error:
     - `/// {var}` ⟶ `write!("{}", self.var)`
     - `/// {0}` ⟶ `write!("{}", self.0)`
     - `/// {var:?}` ⟶ `write!("{:?}", self.var)`
     - `/// {0:?}` ⟶ `write!("{:?}", self.0)`
+- This also works with structs and [generic types][crate::Display#generic-type-parameters]:
+```rust
+/// oh no, an error: {0}
+#[derive(Display)]
+pub struct Error<E>(pub E);
+
+let error: Error<&str> = Error("muahaha i am an error");
+assert!("oh no, an error: muahaha i am an error" == &format!("{}", error));
+```
 
 - Two optional attributes can be added to your types next to the derive:
 
@@ -77,10 +93,10 @@ pub enum DataStoreError {
 ### FAQ
 
 1. **Is this crate `no_std` compatible?**
-    * Yes! This crate implements the `core::fmt::Display` trait not the `std::fmt::Display` trait so it should work in `std` and `no_std` environments. Just add `default-features = false`.
+    * Yes! This crate implements the [`core::fmt::Display`] trait, not the [`std::fmt::Display`] trait, so it should work in `std` and `no_std` environments. Just add `default-features = false`.
 
 2. **Does this crate work with `Path` and `PathBuf` via the `Display` trait?**
-    * Yuuup. This crate uses @dtolnay's [autoref specialization technique](https://github.com/dtolnay/case-studies/blob/master/autoref-specialization/README.md) to add a special trait for types to get the display impl, it then specializes for `Path` and `PathBuf` and when either of these types are found it calls `self.display()` to get a `std::path::Display<'_>` type which can be used with the Display format specifier!
+    * Yuuup. This crate uses @dtolnay's [autoref specialization technique](https://github.com/dtolnay/case-studies/blob/master/autoref-specialization/README.md) to add a special trait for types to get the display impl. It then specializes for `Path` and `PathBuf`, and when either of these types are found, it calls `self.display()` to get a `std::path::Display<'_>` type which can be used with the `Display` format specifier!
 
 
 #### License