add quick_error

quick_error/Cargo.lock

@@ -0,0 +1,14 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "quick-error"
+version = "1.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1d01941d82fa2ab50be1e79e6714289dd7cde78eba4c074bc5a4374f650dfe0"
+
+[[package]]
+name = "quick_error"
+version = "0.1.0"
+dependencies = [
+ "quick-error",
+]

quick_error/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "quick_error"
+version = "0.1.0"
+authors = ["Hatter Jiang@Pixelbook <jht5945@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+quick-error = "1.2.3"
+

quick_error/src/main.rs

@@ -0,0 +1,22 @@
+#[macro_use] extern crate quick_error;
+
+quick_error! {
+    #[derive(Debug)]
+    pub enum SomeError {
+        Io(m: String) {
+            display("{}", m)
+        }
+        Utf8(err: std::str::Utf8Error) {
+            display("utf8 error")
+        }
+    }
+}
+
+// https://docs.rs/quick-error/1.2.3/quick_error/
+fn main() -> Result<(), SomeError> {
+    println!("Hello, world!");
+
+    Err(SomeError::Io("m".to_owned()))
+}
+
+