From c2b9eaa8d3274b8485ab1d7c7cee020460d11e60 Mon Sep 17 00:00:00 2001
From: Tobias Maier <me@maiertobi.de>
Date: Sat, 6 Dec 2025 22:30:42 +0100
Subject: [PATCH] add no-std

---
 Cargo.toml     |  6 +++++-
 src/enums.rs   | 12 ++++++------
 src/lib.rs     |  2 ++
 src/message.rs | 31 ++++++++++++++++++++++++++-----
 src/utils.rs   |  8 ++++++++
 5 files changed, 47 insertions(+), 12 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 92926bf..443b042 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,6 +12,10 @@ categories = ["encoding", "decoding"]
 # [features]
 # json = ["serde_json"]
 
+[features]
+default = ["std"]
+std = []
+
 [dependencies]
 serde = { version = "1.0"}
 # serde_json = { version = "1.0", optional = true }
@@ -19,7 +23,7 @@ thiserror = "2.0.17"
 chrono = { version = "0.4", features = ["serde"] }
 enum_stringify = "0.6.4"
 num_enum = "0.7.5"
-log = "0.4.28"
+log = { version = "0.4" }
 
 
 [lints.clippy]
diff --git a/src/enums.rs b/src/enums.rs
index 3f41457..0ed8fa7 100644
--- a/src/enums.rs
+++ b/src/enums.rs
@@ -1,10 +1,9 @@
-use enum_stringify::EnumStringify;
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 
 /// Message Identifier used in the communication protocol. This is specified by Viessmann
 /// and UNACKED is rarely to never used.
 #[repr(u8)]
-#[derive(Debug, TryFromPrimitive, IntoPrimitive, Clone, Copy, PartialEq, Eq, EnumStringify)]
+#[derive(Debug, TryFromPrimitive, IntoPrimitive, Clone, Copy, PartialEq, Eq)]
 pub enum MessageIdentifier {
     Request = 0x00,
     Response = 0x01,
@@ -12,11 +11,12 @@ pub enum MessageIdentifier {
     CommError = 0x03,
 }
 
-/// Function Code used in the communication protocol. This is specified by Viessmann
-/// and Read and Write are usually used for simpler values, RPC can maybe be used for
-/// more complex things, but this is currently unclear
+/// Function Code used in the communication protocol.
+/// 
+/// This is specified by Viessmann and Read and Write are usually used for simpler values, 
+/// RPC can maybe be used for more complex things, but this is currently unclear
 #[repr(u8)]
-#[derive(Debug, TryFromPrimitive, IntoPrimitive, Clone, Copy, PartialEq, Eq, EnumStringify)]
+#[derive(Debug, TryFromPrimitive, IntoPrimitive, Clone, Copy, PartialEq, Eq)]
 pub enum FunctionCode {
     VirtualREAD = 0x01,
     VirtualWRITE = 0x02,
diff --git a/src/lib.rs b/src/lib.rs
index 241e0bc..a162d32 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,5 @@
+#![cfg_attr(not(feature = "std"), no_std)]
+
 mod message;
 mod enums;
 mod utils;
diff --git a/src/message.rs b/src/message.rs
index 6f68cbf..ef15ceb 100644
--- a/src/message.rs
+++ b/src/message.rs
@@ -1,6 +1,19 @@
-use log::warn;
-use thiserror::Error;
+use log::{warn, error};
 
+// Use std::vec when std exists, otherwise alloc::vec
+#[cfg(feature = "std")]
+use std::vec;
+
+#[cfg(not(feature = "std"))]
+extern crate alloc;
+
+#[cfg(not(feature = "std"))]
+use alloc::vec;
+
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
+
+use thiserror::Error;
 use crate::{enums::{FunctionCode, MessageIdentifier}, utils::calculate_checksum};
 
 #[derive(PartialEq, Eq, Debug)]
@@ -167,7 +180,7 @@ impl Protocol300Message {
 pub enum MessageCreationError {
     /// The data length is longer than u8
     #[error("Data too long")]
-    DataTooLong(#[from] std::num::TryFromIntError),
+    DataTooLong(#[from] core::num::TryFromIntError),
 
 }
 
@@ -190,7 +203,7 @@ pub enum MessageDecodingError {
     InvalidTelegramStart(u8),
     /// Error getiting the length of the bytes slice, should never happen
     #[error("Error getting the length of the bytes slice")]
-    NoLength(#[from] std::num::TryFromIntError),
+    NoLength(#[from] core::num::TryFromIntError),
     /// The advertiesed telegram length and actual length do not match
     #[error("The advertiesed telegram length and actual length do not match")]
     LengthMismatch(),
@@ -204,7 +217,15 @@ pub enum MessageDecodingError {
 
 #[cfg(test)]
 mod tests {
-    use crate::{enums::{FunctionCode, MessageIdentifier}, message::{MessageCreationError, Protocol300Message}, utils::calculate_checksum};
+    use crate::{enums::{FunctionCode, MessageIdentifier}, message::{MessageCreationError, Protocol300Message}};
+    #[cfg(not(feature = "std"))]
+    extern crate alloc;
+
+    #[cfg(not(feature = "std"))]
+    use alloc::vec;
+
+    #[cfg(not(feature = "std"))]
+    use alloc::vec::Vec;
 
 
     #[test]
diff --git a/src/utils.rs b/src/utils.rs
index fc1d522..e95fdf5 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -18,6 +18,14 @@ pub fn calculate_checksum(length: u8, message_identifier: MessageIdentifier, fun
 #[cfg(test)]
 mod tests {
     use crate::{enums::{FunctionCode, MessageIdentifier}, message::Protocol300Message, utils::calculate_checksum};
+    #[cfg(not(feature = "std"))]
+    extern crate alloc;
+
+    #[cfg(not(feature = "std"))]
+    use alloc::vec;
+
+    #[cfg(not(feature = "std"))]
+    use alloc::vec::Vec;
 
     #[test]
     fn test_check_checksum_1() {