Merge pull request #22 from noislabs/no-std

The remaining no_std work

.github/workflows/test.yml

@@ -11,7 +11,7 @@ jobs:
   build:
     strategy:
       matrix:
-        rust-version: ["1.70.0", "1.75.0"]
+        rust-version: ["1.70.0", "1.74.0", "1.78.0"]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -22,10 +22,23 @@ jobs:
       - run: cargo build
       - run: cargo build --target wasm32-unknown-unknown
 
+  build-no_std:
+    strategy:
+      matrix:
+        rust-version: ["1.70.0", "1.74.0", "1.78.0"]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: "${{ matrix.rust-version }}"
+          targets: "thumbv6m-none-eabi"
+      - run: cargo check --no-default-features --target thumbv6m-none-eabi
+
   test:
     strategy:
       matrix:
-        rust-version: ["1.70.0", "1.75.0"]
+        rust-version: ["1.70.0", "1.74.0", "1.78.0"]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -34,10 +47,22 @@ jobs:
           toolchain: "${{ matrix.rust-version }}"
       - run: cargo test
 
+  test-no_std:
+    strategy:
+      matrix:
+        rust-version: ["1.70.0", "1.74.0", "1.78.0"]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: "${{ matrix.rust-version }}"
+      - run: cargo test --no-default-features
+
   clippy:
     strategy:
       matrix:
-        rust-version: ["1.70.0", "1.75.0"]
+        rust-version: ["1.70.0", "1.74.0", "1.78.0"]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4

README.md

@@ -61,3 +61,13 @@ let deserialized = Bufany::deserialize(&data).unwrap(); // data from above
 let id = deserialized.uint64(1).unwrap(); // 4
 let title = deserialized.string(2).unwrap(); // "hello"
 ```
+
+## `no_std` support
+
+Since version 0.5.0 there is a default `std` feature. If you remove that, the library is built with `no_std` support.
+As the anybuf maintainers do not require `no_std` support this is provided at a best effort basis and might be broken.
+
+```toml
+[dependencies]
+anybuf = { version = "0.5.0", default-features = false }
+```

src/anybuf.rs

@@ -1,3 +1,5 @@
+use alloc::vec::Vec;
+
 use crate::varint::{to_zigzag32, to_zigzag64, unsigned_varint_encode};
 
 /// The protobuf wire types
@@ -538,6 +540,9 @@ mod tests {
     use super::*;
     use hex_literal::hex;
 
+    use alloc::string::{String, ToString};
+    use alloc::vec;
+
     #[test]
     fn new_returns_empty_data() {
         let data = Anybuf::new();

src/bufany.rs

@@ -1,4 +1,6 @@
-use std::collections::HashMap;
+use alloc::collections::BTreeMap;
+use alloc::string::String;
+use alloc::vec::Vec;
 
 use crate::{
     slice_reader::SliceReader,
@@ -34,7 +36,7 @@ use crate::{
 #[derive(Debug)]
 pub struct Bufany<'a> {
     // A map from field number to decoded value.
-    fields: HashMap<u32, Vec<Value<'a>>>,
+    fields: BTreeMap<u32, Vec<Value<'a>>>,
     // A vector that is always empty and has the lifetime we need.
     empty_vec: Vec<Value<'a>>,
 }
@@ -820,6 +822,8 @@ mod tests {
     use crate::Anybuf;
 
     use super::*;
+    use alloc::string::ToString;
+    use alloc::vec;
 
     #[test]
     fn deserialize_works() {

src/lib.rs

@@ -26,6 +26,10 @@
 //! - Packed encoding for repeated fields
 //! - Maps support (but you can use the equivalent [encoding via repeated messages](https://protobuf.dev/programming-guides/encoding/#maps))
 
+#![cfg_attr(not(feature = "std"), no_std)]
+
+extern crate alloc;
+
 mod anybuf;
 mod bufany;
 mod slice_reader;

src/slice_reader.rs

@@ -57,6 +57,8 @@ impl<'x> SliceReader<'x> {
 mod tests {
     use super::*;
 
+    use alloc::vec;
+
     #[test]
     fn read_array_works() {
         let original = vec![5u8, 7, 234, 2, 45, 0, 12, 32, 192];

src/varint.rs

@@ -1,3 +1,5 @@
+use alloc::vec::Vec;
+
 use crate::slice_reader::SliceReader;
 
 #[allow(dead_code)]
@@ -69,6 +71,8 @@ pub fn read_unsigned_varint(data: &mut SliceReader) -> Option<u64> {
 mod tests {
     use super::*;
 
+    use alloc::vec;
+
     #[test]
     fn to_zigzag32_works() {
         // values from https://protobuf.dev/programming-guides/encoding/