feat: impls for Box and String conversions (#458)

Co-authored-by: Rob Ede <robjtede@icloud.com>

bytestring/CHANGES.md

@@ -2,6 +2,9 @@
 
 ## Unreleased - 2022-xx-xx
 - Minimum supported Rust version (MSRV) is now 1.49.
+- Implement `From<Box<str>>` and `Into<String>`. [#458]
+
+[#458]: https://github.com/actix/actix-net/pull/458
 
 
 ## 1.0.0 - 2020-12-31

bytestring/src/lib.rs

@@ -6,7 +6,11 @@
 
 extern crate alloc;
 
-use alloc::{string::String, vec::Vec};
+use alloc::{
+    boxed::Box,
+    string::{String, ToString},
+    vec::Vec,
+};
 use core::{borrow, convert::TryFrom, fmt, hash, ops, str};
 
 use bytes::Bytes;
@@ -110,6 +114,20 @@ impl From<&str> for ByteString {
     }
 }
 
+impl From<Box<str>> for ByteString {
+    #[inline]
+    fn from(value: Box<str>) -> Self {
+        Self(Bytes::from(value.into_boxed_bytes()))
+    }
+}
+
+impl From<ByteString> for String {
+    #[inline]
+    fn from(value: ByteString) -> Self {
+        value.to_string()
+    }
+}
+
 impl TryFrom<&[u8]> for ByteString {
     type Error = str::Utf8Error;