builder API

Author: marvin-j97

Cargo.toml

@@ -2,9 +2,9 @@
 name = "byteview"
 description = "Thin, immutable zero-copy slice type"
 license = "MIT OR Apache-2.0"
-version = "0.7.0"
+version = "0.8.0"
 edition = "2021"
-rust-version = "1.74"
+rust-version = "1.81"
 readme = "README.md"
 include = ["src/**/*", "LICENSE-APACHE", "LICENSE-MIT", "README.md"]
 repository = "https://github.com/fjall-rs/byteview"
@@ -28,9 +28,6 @@ rand = "0.9.0"
 # TODO: Need MSRV 1.81
 # rkyv = { version = "0.8.10", features = ["bytecheck", "unaligned"] }
 
-# half 2.5.0 has MSRV 1.81
-half = "=2.4.0"
-
 [[bench]]
 name = "bench"
 harness = false

src/builder.rs

@@ -0,0 +1,33 @@
+use crate::ByteView;
+
+/// A builder for a [`ByteView`] that allows mutation before freezing it.
+pub struct Builder(ByteView);
+
+impl Builder {
+    /// Creates a new builder.
+    #[must_use]
+    pub const fn new(inner: ByteView) -> Self {
+        Self(inner)
+    }
+
+    /// Converts the builder into a [`ByteView`], making it immutable.
+    #[must_use]
+    pub fn freeze(mut self) -> ByteView {
+        self.0.update_prefix();
+        self.0
+    }
+}
+
+impl std::ops::Deref for Builder {
+    type Target = [u8];
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl std::ops::DerefMut for Builder {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        self.0.get_mut_slice()
+    }
+}

src/byteview.rs

@@ -12,6 +12,8 @@ use std::{
     },
 };
 
+pub use crate::builder::Builder;
+
 #[cfg(target_pointer_width = "64")]
 const INLINE_SIZE: usize = 20;
 
@@ -207,6 +209,12 @@ impl Drop for Mutator<'_> {
 }
 
 impl ByteView {
+    #[doc(hidden)]
+    #[must_use]
+    pub fn builder_unzeroed(len: usize) -> Builder {
+        Builder::new(Self::with_size_unzeroed(len))
+    }
+
     fn prefix(&self) -> &[u8] {
         let len = PREFIX_SIZE.min(self.len());
 
@@ -218,7 +226,7 @@ impl ByteView {
         self.len() <= INLINE_SIZE
     }
 
-    fn update_prefix(&mut self) {
+    pub(crate) fn update_prefix(&mut self) {
         if !self.is_inline() {
             unsafe {
                 let slice_ptr: &[u8] = &*self;
@@ -639,7 +647,7 @@ impl ByteView {
         unsafe { self.trailer.short.len as usize }
     }
 
-    fn get_mut_slice(&mut self) -> &mut [u8] {
+    pub(crate) fn get_mut_slice(&mut self) -> &mut [u8] {
         let len = self.len();
 
         if self.is_inline() {

src/lib.rs

@@ -47,10 +47,11 @@
     clippy::needless_lifetimes
 )]
 
+mod builder;
 mod byteview;
 mod strview;
 
 pub use {byteview::ByteView, strview::StrView};
 
 #[doc(hidden)]
-pub use byteview::Mutator;
+pub use byteview::{Builder, Mutator};