From fc15b9ee63fe19cf9814ab5acd705c5289dc2682 Mon Sep 17 00:00:00 2001
From: stelzo <stelzo@steado.de>
Date: Wed, 15 May 2024 18:43:58 +0200
Subject: [PATCH 1/5] no_std compatible (#18)

---
 Cargo.toml      |   5 +-
 README.md       |   4 ++
 src/iterator.rs |  35 +++++++---
 src/lib.rs      | 172 +++++++++++++++++++++++++++++++++---------------
 src/points.rs   |  33 +++++++++-
 src/ros.rs      |   3 +
 6 files changed, 185 insertions(+), 67 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 9efc73c..063fed5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,7 +35,7 @@ r2r = { version = "0.8.4", optional = true }
 rayon = { version = "1", optional = true }
 nalgebra = { version = "0", optional = true }
 rpcl2_derive = { path = "./rpcl2_derive", optional = true }
-type-layout = { version = "0.2", optional = true }
+type-layout = { git = "https://github.com/stelzo/type-layout", branch = "syn2", optional = true }
 
 [dev-dependencies]
 rand = "0.8"
@@ -51,8 +51,9 @@ r2r_msg = ["dep:r2r"]
 rayon = ["dep:rayon"]
 derive = ["dep:rpcl2_derive", "dep:type-layout"]
 nalgebra = ["dep:nalgebra"]
+std = []
 
-default = ["derive"]
+default = ["derive", "std"]
 
 [package.metadata.docs.rs]
 features = ["derive", "nalgebra", "rayon"]
diff --git a/README.md b/README.md
index 9bf771d..ae1d811 100644
--- a/README.md
+++ b/README.md
@@ -95,6 +95,10 @@ The results are measured on an Intel i7-14700 with benchmarks from [this reposit
 
 For minimizing the conversion overhead in general, always use the functions that best fit your use case.
 
+## `#[no_std]`
+
+The `_iter` conversions are compatible with `#[no_std]` environments when an allocator is provided. This is due to the fact that names for point fields do not have a maximum length, and PointCloud2 data vectors can have arbitrary sizes. Use `default-features = false` to disable std for this crate.
+
 ## License
 
 [MIT](https://choosealicense.com/licenses/mit/)
diff --git a/src/iterator.rs b/src/iterator.rs
index 4c47fbc..938d256 100644
--- a/src/iterator.rs
+++ b/src/iterator.rs
@@ -1,10 +1,19 @@
-//! Iterator implementations for PointCloud2Msg including a parallel iterator for rayon.
+//! Iterator implementations for [`PointCloud2Msg`] including a parallel iterator for rayon.
 use crate::{
     Endian, FieldDatatype, Fields, MsgConversionError, PointCloud2Msg, PointConvertible, PointData,
     RPCL2Point,
 };
 
-/// The PointCloudIterator provides a an iterator abstraction of the PointCloud2Msg.
+#[cfg(not(feature = "std"))]
+use alloc::string::String;
+
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
+
+#[cfg(not(feature = "std"))]
+use alloc::borrow::ToOwned;
+
+/// The PointCloudIterator provides a an iterator abstraction of the [`PointCloud2Msg`].
 ///
 /// The iterator is defined at compile time, so the point has to be described via template arguments.
 ///
@@ -19,7 +28,7 @@ use crate::{
 /// let msg: r2r::sensor_msgs::msg::PointCloud2 = internal_msg.into();
 /// let converted: ros_pointcloud2::PointCloud2Msg = msg.into();
 ///
-/// ros_pointcloud2 supports r2r, rclrs and rosrust as conversion targets out of the box via feature flags.
+/// `ros_pointcloud2` supports r2r, rclrs and rosrust as conversion targets out of the box via feature flags.
 ///
 pub struct PointCloudIterator<const N: usize, C>
 where
@@ -28,7 +37,7 @@ where
     iteration: usize,
     iteration_back: usize,
     data: ByteBufferView<N>,
-    phantom_c: std::marker::PhantomData<C>, // internally used for pdata names array
+    phantom_c: core::marker::PhantomData<C>, // internally used for pdata names array
 }
 
 #[cfg(feature = "rayon")]
@@ -156,7 +165,10 @@ where
 }
 
 struct ByteBufferView<const N: usize> {
+    #[cfg(feature = "rayon")]
     data: std::sync::Arc<[u8]>,
+    #[cfg(not(feature = "rayon"))]
+    data: Vec<u8>,
     start_point_idx: usize,
     end_point_idx: usize,
     point_step_size: usize,
@@ -176,7 +188,10 @@ impl<const N: usize> ByteBufferView<N> {
         endian: Endian,
     ) -> Self {
         Self {
+            #[cfg(feature = "rayon")]
             data: std::sync::Arc::<[u8]>::from(data),
+            #[cfg(not(feature = "rayon"))]
+            data,
             start_point_idx,
             end_point_idx,
             point_step_size,
@@ -191,7 +206,7 @@ impl<const N: usize> ByteBufferView<N> {
         self.end_point_idx - self.start_point_idx + 1
     }
 
-    #[inline(always)]
+    #[inline]
     fn point_at(&self, idx: usize) -> RPCL2Point<N> {
         let offset = (self.start_point_idx + idx) * self.point_step_size;
         let mut pdata = [PointData::default(); N];
@@ -244,8 +259,8 @@ where
 {
     type Error = MsgConversionError;
 
-    /// Convert a PointCloud2Msg into an iterator.
-    /// Converting a PointCloud2Msg into an iterator is a fallible operation since the message could contain a subset of the required fields.
+    /// Convert a [`PointCloud2Msg`] into an iterator.
+    /// The conversion to an iterator is a fallible operation since the message could contain a subset of the required fields.
     ///
     /// The theoretical time complexity is O(n) where n is the number of fields defined in the message for a single point which is typically small.
     /// It therefore has a constant time complexity O(1) for practical purposes.
@@ -332,7 +347,7 @@ where
             iteration: 0,
             iteration_back: cloud_length - 1,
             data,
-            phantom_c: std::marker::PhantomData,
+            phantom_c: core::marker::PhantomData,
         })
     }
 }
@@ -342,16 +357,18 @@ where
     C: Fields<N>,
 {
     #[inline]
+    #[must_use]
     fn from_byte_buffer_view(data: ByteBufferView<N>) -> Self {
         Self {
             iteration: 0,
             iteration_back: data.len() - 1,
             data,
-            phantom_c: std::marker::PhantomData,
+            phantom_c: core::marker::PhantomData,
         }
     }
 
     #[inline]
+    #[must_use]
     pub fn split_at(self, point_index: usize) -> (Self, Self) {
         let (left_data, right_data) = self.data.split_at(point_index);
         (
diff --git a/src/lib.rs b/src/lib.rs
index 92c32a2..443e9ad 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -125,10 +125,17 @@
 //!     pub intensity: f32,
 //! }
 //! ```
-
 #![crate_type = "lib"]
 #![warn(clippy::print_stderr)]
 #![warn(clippy::print_stdout)]
+#![warn(clippy::unwrap_used)]
+#![warn(clippy::cargo)]
+#![warn(clippy::std_instead_of_core)]
+#![warn(clippy::alloc_instead_of_core)]
+#![warn(clippy::std_instead_of_alloc)]
+#![cfg_attr(not(feature = "std"), no_std)]
+// Setup an allocator with #[global_allocator]
+// see: https://doc.rust-lang.org/std/alloc/trait.GlobalAlloc.html
 
 pub mod points;
 pub mod prelude;
@@ -136,46 +143,65 @@ pub mod ros;
 
 pub mod iterator;
 
-use std::num::TryFromIntError;
-use std::str::FromStr;
-
 use crate::ros::{HeaderMsg, PointFieldMsg};
 
+use core::str::FromStr;
+
+#[cfg(not(feature = "std"))]
+#[macro_use]
+extern crate alloc;
+
+#[cfg(not(feature = "std"))]
+use alloc::string::String;
+
+#[cfg(not(feature = "std"))]
+use alloc::vec::Vec;
+
 /// All errors that can occur while converting to or from the message type.
 #[derive(Debug)]
 pub enum MsgConversionError {
     InvalidFieldFormat,
+    #[cfg(feature = "std")]
     UnsupportedFieldType(String),
+    #[cfg(not(feature = "std"))]
+    UnsupportedFieldType,
     DataLengthMismatch,
     FieldsNotFound(Vec<String>),
     UnsupportedFieldCount,
     NumberConversion,
 }
 
-impl From<TryFromIntError> for MsgConversionError {
-    fn from(_: TryFromIntError) -> Self {
+impl From<core::num::TryFromIntError> for MsgConversionError {
+    fn from(_: core::num::TryFromIntError) -> Self {
         MsgConversionError::NumberConversion
     }
 }
 
-impl std::fmt::Display for MsgConversionError {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+impl core::fmt::Display for MsgConversionError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         match self {
             MsgConversionError::InvalidFieldFormat => {
                 write!(f, "The field does not match the expected datatype.")
             }
+            #[cfg(feature = "std")]
             MsgConversionError::UnsupportedFieldType(datatype) => {
                 write!(
                     f,
-                    "The field datatype is not supported by the ROS message description: {}",
-                    datatype
+                    "The field datatype is not supported by the ROS message description: {datatype}"
+                )
+            }
+            #[cfg(not(feature = "std"))]
+            MsgConversionError::UnsupportedFieldType => {
+                write!(
+                    f,
+                    "There is an unsupported field type in the ROS message description."
                 )
             }
             MsgConversionError::DataLengthMismatch => {
                 write!(f, "The length of the byte buffer in the message does not match the expected length computed from the fields, indicating a corrupted or malformed message.")
             }
             MsgConversionError::FieldsNotFound(fields) => {
-                write!(f, "Some fields are not found in the message: {:?}", fields)
+                write!(f, "Some fields are not found in the message: {fields:?}")
             }
             MsgConversionError::UnsupportedFieldCount => {
                 write!(
@@ -190,6 +216,7 @@ impl std::fmt::Display for MsgConversionError {
     }
 }
 
+#[cfg(feature = "std")]
 impl std::error::Error for MsgConversionError {
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
         None
@@ -246,11 +273,12 @@ enum ByteSimilarity {
     Different,
 }
 
-/// Creating a CloudDimensions type with the builder pattern to avoid invalid states when using 1-row point clouds.
+/// Creating a [`CloudDimensions`] type with the builder pattern to avoid invalid states when using 1-row point clouds.
 #[derive(Clone, Debug)]
 pub struct CloudDimensionsBuilder(usize);
 
 impl CloudDimensionsBuilder {
+    #[must_use]
     pub fn new_with_width(width: usize) -> Self {
         Self(width)
     }
@@ -263,12 +291,12 @@ impl CloudDimensionsBuilder {
 
         Ok(CloudDimensions {
             width,
-            height: if self.0 > 0 { 1 } else { 0 },
+            height: u32::from(self.0 > 0),
         })
     }
 }
 
-/// Creating a PointCloud2Msg with the builder pattern to avoid invalid states.
+/// Creating a [`PointCloud2Msg`] with the builder pattern to avoid invalid states.
 #[derive(Clone, Debug, Default)]
 pub struct PointCloud2MsgBuilder {
     header: HeaderMsg,
@@ -282,50 +310,63 @@ pub struct PointCloud2MsgBuilder {
 }
 
 impl PointCloud2MsgBuilder {
+    #[must_use]
     pub fn new() -> Self {
         Self::default()
     }
 
+    #[must_use]
     pub fn header(mut self, header: HeaderMsg) -> Self {
         self.header = header;
         self
     }
 
+    #[must_use]
     pub fn width(mut self, width: u32) -> Self {
         self.width = width;
         self
     }
 
+    #[must_use]
     pub fn fields(mut self, fields: Vec<PointFieldMsg>) -> Self {
         self.fields = fields;
         self
     }
 
+    #[must_use]
     pub fn endian(mut self, is_big_endian: bool) -> Self {
         self.is_big_endian = is_big_endian;
         self
     }
 
+    #[must_use]
     pub fn point_step(mut self, point_step: u32) -> Self {
         self.point_step = point_step;
         self
     }
 
+    #[must_use]
     pub fn row_step(mut self, row_step: u32) -> Self {
         self.row_step = row_step;
         self
     }
 
+    #[must_use]
     pub fn data(mut self, data: Vec<u8>) -> Self {
         self.data = data;
         self
     }
 
+    #[must_use]
     pub fn dense(mut self, is_dense: bool) -> Self {
         self.is_dense = is_dense;
         self
     }
 
+    /// Build the [`PointCloud2Msg`] from the builder.
+    ///
+    /// # Errors
+    /// Returns an error if the fields are empty, the field count is not 1, the field format is invalid, the data length does not match the point step, or the field size is too large.
     pub fn build(self) -> Result<PointCloud2Msg, MsgConversionError> {
         if self.fields.is_empty() {
             return Err(MsgConversionError::FieldsNotFound(vec![]));
@@ -382,7 +423,7 @@ pub struct CloudDimensions {
 
 impl PointCloud2Msg {
     #[cfg(feature = "derive")]
-    #[inline(always)]
+    #[inline]
     fn byte_similarity<const N: usize, C>(&self) -> Result<ByteSimilarity, MsgConversionError>
     where
         C: PointConvertible<N>,
@@ -405,7 +446,8 @@ impl PointCloud2Msg {
                     size,
                     count,
                 } => {
-                    let f_translated = field_names[field_counter].to_string();
+                    let f_translated = String::from_str(field_names[field_counter])
+                        .expect("Field name is not a valid string.");
                     field_counter += 1;
 
                     if msg_f.name != f_translated
@@ -431,7 +473,7 @@ impl PointCloud2Msg {
         })
     }
 
-    /// Create a PointCloud2Msg from any iterable type.
+    /// Create a [`PointCloud2Msg`] from any iterable type.
     ///
     /// # Example
     /// ```
@@ -493,7 +535,7 @@ impl PointCloud2Msg {
 
             point.fields.iter().for_each(|pdata| {
                 let truncated_bytes = unsafe {
-                    std::slice::from_raw_parts(pdata.bytes.as_ptr(), pdata.datatype.size())
+                    core::slice::from_raw_parts(pdata.bytes.as_ptr(), pdata.datatype.size())
                 };
                 cloud.data.extend_from_slice(truncated_bytes);
             });
@@ -518,7 +560,7 @@ impl PointCloud2Msg {
         Self::try_from_vec(iterable.collect::<Vec<_>>())
     }
 
-    /// Create a PointCloud2Msg from a Vec of points.
+    /// Create a [`PointCloud2Msg`] from a Vec of points.
     /// Since the point type is known at compile time, the conversion is done by direct copy.
     ///
     /// # Example
@@ -532,6 +574,9 @@ impl PointCloud2Msg {
     ///
     /// let msg_out = PointCloud2Msg::try_from_vec(cloud_points).unwrap();
     /// ```
+    ///
+    /// # Errors
+    /// Returns an error if the byte buffer does not match the expected layout or the message contains other discrepancies.
     #[cfg(feature = "derive")]
     pub fn try_from_vec<const N: usize, C>(vec: Vec<C>) -> Result<Self, MsgConversionError>
     where
@@ -552,7 +597,8 @@ impl PointCloud2Msg {
                     let mut offset = 0;
                     let mut fields: Vec<PointFieldMsg> = Vec::with_capacity(layout.fields.len());
                     for f in layout.fields.into_iter() {
-                        let f_translated = field_names[fields.len()].to_string();
+                        let f_translated = String::from_str(field_names[fields.len()])
+                            .expect("Field name is not a valid string.");
                         match f {
                             PointField::Field {
                                 datatype,
@@ -585,9 +631,9 @@ impl PointCloud2Msg {
                 cloud.data.resize(bytes_total, u8::default());
                 let raw_data: *mut C = cloud.data.as_ptr() as *mut C;
                 unsafe {
-                    std::ptr::copy_nonoverlapping(
-                        vec.as_ptr() as *const u8,
-                        raw_data as *mut u8,
+                    core::ptr::copy_nonoverlapping(
+                        vec.as_ptr().cast::<u8>(),
+                        raw_data.cast::<u8>(),
                         bytes_total,
                     );
                 }
@@ -601,7 +647,7 @@ impl PointCloud2Msg {
         }
     }
 
-    /// Convert the PointCloud2Msg to a Vec of points.
+    /// Convert the [`PointCloud2Msg`] to a Vec of points.
     ///
     /// # Example
     /// ```
@@ -616,6 +662,9 @@ impl PointCloud2Msg {
     /// let cloud_points_out: Vec<PointXYZ> = msg_out.try_into_vec().unwrap();
     /// assert_eq!(1.0, cloud_points_out.get(0).unwrap().x);
     /// ```
+    ///
+    /// # Errors
+    /// Returns an error if the byte buffer does not match the expected layout or the message contains other discrepancies.
     #[cfg(feature = "derive")]
     pub fn try_into_vec<const N: usize, C>(self) -> Result<Vec<C>, MsgConversionError>
     where
@@ -631,12 +680,12 @@ impl PointCloud2Msg {
 
                 let cloud_width = self.dimensions.width as usize;
                 let point_step = self.point_step as usize;
-                let mut vec = Vec::with_capacity(cloud_width);
+                let mut vec: Vec<C> = Vec::with_capacity(cloud_width);
                 if bytematch {
                     unsafe {
-                        std::ptr::copy_nonoverlapping(
+                        core::ptr::copy_nonoverlapping(
                             self.data.as_ptr(),
-                            vec.as_mut_ptr() as *mut u8,
+                            vec.as_mut_ptr().cast::<u8>(),
                             self.data.len(),
                         );
                         vec.set_len(cloud_width);
@@ -644,7 +693,7 @@ impl PointCloud2Msg {
                 } else {
                     unsafe {
                         for i in 0..cloud_width {
-                            let point_ptr = self.data.as_ptr().add(i * point_step) as *const C;
+                            let point_ptr = self.data.as_ptr().add(i * point_step).cast::<C>();
                             let point = point_ptr.read();
                             vec.push(point);
                         }
@@ -657,7 +706,7 @@ impl PointCloud2Msg {
         }
     }
 
-    /// Convert the PointCloud2Msg to an iterator.
+    /// Convert the [`PointCloud2Msg`] to an iterator.
     ///
     /// # Example
     /// ```
@@ -671,6 +720,8 @@ impl PointCloud2Msg {
     /// let msg_out = PointCloud2Msg::try_from_iter(cloud_points).unwrap();
     /// let cloud_points_out = msg_out.try_into_iter().unwrap().collect::<Vec<PointXYZ>>();
     /// ```
+    /// # Errors
+    /// Returns an error if the byte buffer does not match the expected layout or the message contains other discrepancies.
     pub fn try_into_iter<const N: usize, C>(
         self,
     ) -> Result<impl Iterator<Item = C>, MsgConversionError>
@@ -724,7 +775,7 @@ impl<const N: usize> Default for RPCL2Point<N> {
     }
 }
 
-impl<const N: usize> std::ops::Index<usize> for RPCL2Point<N> {
+impl<const N: usize> core::ops::Index<usize> for RPCL2Point<N> {
     type Output = PointData;
 
     fn index(&self, index: usize) -> &Self::Output {
@@ -931,7 +982,7 @@ impl TryFrom<type_layout::TypeLayoutInfo> for TypeLayoutInfo {
 /// ```
 #[derive(Debug, Clone, Copy)]
 pub struct PointData {
-    bytes: [u8; std::mem::size_of::<f64>()],
+    bytes: [u8; core::mem::size_of::<f64>()],
     endian: Endian,
     datatype: FieldDatatype,
 }
@@ -939,7 +990,7 @@ pub struct PointData {
 impl Default for PointData {
     fn default() -> Self {
         Self {
-            bytes: [u8::default(); std::mem::size_of::<f64>()],
+            bytes: [u8::default(); core::mem::size_of::<f64>()],
             datatype: FieldDatatype::F32,
             endian: Endian::default(),
         }
@@ -947,13 +998,13 @@ impl Default for PointData {
 }
 
 impl PointData {
-    /// Create a new PointData from a value.
+    /// Create a new [`PointData`] from a value.
     ///
     /// # Example
     /// ```
     /// let pdata = ros_pointcloud2::PointData::new(1.0);
     /// ```
-    #[inline(always)]
+    #[inline]
     pub fn new<T: FromBytes>(value: T) -> Self {
         Self {
             bytes: value.into().raw(),
@@ -962,24 +1013,24 @@ impl PointData {
         }
     }
 
-    #[inline(always)]
+    #[inline]
     fn from_buffer(data: &[u8], offset: usize, datatype: FieldDatatype, endian: Endian) -> Self {
         debug_assert!(data.len() >= offset + datatype.size());
-        let bytes = [u8::default(); std::mem::size_of::<f64>()];
+        let bytes = [u8::default(); core::mem::size_of::<f64>()];
         unsafe {
             let data_ptr = data.as_ptr().add(offset);
             let bytes_ptr = bytes.as_ptr() as *mut u8;
-            std::ptr::copy_nonoverlapping(data_ptr, bytes_ptr, datatype.size());
+            core::ptr::copy_nonoverlapping(data_ptr, bytes_ptr, datatype.size());
         }
 
         Self {
             bytes,
-            datatype,
             endian,
+            datatype,
         }
     }
 
-    /// Get the numeric value from the PointData description.
+    /// Get the numeric value from the [`PointData`] description.
     ///
     /// # Example
     /// ```
@@ -987,6 +1038,7 @@ impl PointData {
     /// let pdata = ros_pointcloud2::PointData::new(original_data);
     /// let my_data: f64 = pdata.get();
     /// ```
+    #[must_use]
     pub fn get<T: FromBytes>(&self) -> T {
         match self.endian {
             Endian::Big => T::from_be_bytes(PointDataBuffer::new(self.bytes)),
@@ -1062,22 +1114,22 @@ pub enum FieldDatatype {
 }
 
 impl FieldDatatype {
+    #[must_use]
     pub fn size(&self) -> usize {
         match self {
-            FieldDatatype::U8 => std::mem::size_of::<u8>(),
-            FieldDatatype::U16 => std::mem::size_of::<u16>(),
-            FieldDatatype::U32 => std::mem::size_of::<u32>(),
-            FieldDatatype::I8 => std::mem::size_of::<i8>(),
-            FieldDatatype::I16 => std::mem::size_of::<i16>(),
-            FieldDatatype::I32 => std::mem::size_of::<i32>(),
-            FieldDatatype::F32 => std::mem::size_of::<f32>(),
-            FieldDatatype::F64 => std::mem::size_of::<f64>(),
-            FieldDatatype::RGB => std::mem::size_of::<f32>(), // packed in f32
+            FieldDatatype::U8 => core::mem::size_of::<u8>(),
+            FieldDatatype::U16 => core::mem::size_of::<u16>(),
+            FieldDatatype::U32 => core::mem::size_of::<u32>(),
+            FieldDatatype::I8 => core::mem::size_of::<i8>(),
+            FieldDatatype::I16 => core::mem::size_of::<i16>(),
+            FieldDatatype::I32 => core::mem::size_of::<i32>(),
+            FieldDatatype::F32 | FieldDatatype::RGB => core::mem::size_of::<f32>(), // packed in f32
+            FieldDatatype::F64 => core::mem::size_of::<f64>(),
         }
     }
 }
 
-impl FromStr for FieldDatatype {
+impl core::str::FromStr for FieldDatatype {
     type Err = MsgConversionError;
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
@@ -1091,7 +1143,10 @@ impl FromStr for FieldDatatype {
             "i8" => Ok(FieldDatatype::I8),
             "i16" => Ok(FieldDatatype::I16),
             "rgb" => Ok(FieldDatatype::RGB),
+            #[cfg(feature = "std")]
             _ => Err(MsgConversionError::UnsupportedFieldType(s.into())),
+            #[cfg(not(feature = "std"))]
+            _ => Err(MsgConversionError::UnsupportedFieldType),
         }
     }
 }
@@ -1169,7 +1224,10 @@ impl TryFrom<u8> for FieldDatatype {
             6 => Ok(FieldDatatype::U32),
             7 => Ok(FieldDatatype::F32),
             8 => Ok(FieldDatatype::F64),
+            #[cfg(feature = "std")]
             _ => Err(MsgConversionError::UnsupportedFieldType(value.to_string())),
+            #[cfg(not(feature = "std"))]
+            _ => Err(MsgConversionError::UnsupportedFieldType),
         }
     }
 }
@@ -1183,9 +1241,8 @@ impl From<FieldDatatype> for u8 {
             FieldDatatype::U16 => 4,
             FieldDatatype::I32 => 5,
             FieldDatatype::U32 => 6,
-            FieldDatatype::F32 => 7,
+            FieldDatatype::F32 | FieldDatatype::RGB => 7, // RGB is marked as f32 in the buffer
             FieldDatatype::F64 => 8,
-            FieldDatatype::RGB => 7, // RGB is marked as f32 in the buffer
         }
     }
 }
@@ -1200,10 +1257,10 @@ impl TryFrom<&ros::PointFieldMsg> for FieldDatatype {
 
 /// Byte buffer alias for endian-aware point data reading and writing.
 ///
-/// It uses a fixed size buffer of 8 bytes since the largest supported datatype for PointFieldMsg is f64.
+/// It uses a fixed size buffer of 8 bytes since the largest supported datatype for [`ros::PointFieldMsg`] is f64.
 pub struct PointDataBuffer([u8; 8]);
 
-impl std::ops::Index<usize> for PointDataBuffer {
+impl core::ops::Index<usize> for PointDataBuffer {
     type Output = u8;
 
     fn index(&self, index: usize) -> &Self::Output {
@@ -1212,18 +1269,22 @@ impl std::ops::Index<usize> for PointDataBuffer {
 }
 
 impl PointDataBuffer {
+    #[must_use]
     pub fn new(data: [u8; 8]) -> Self {
         Self(data)
     }
 
+    #[must_use]
     pub fn as_slice(&self) -> &[u8] {
         &self.0
     }
 
+    #[must_use]
     pub fn raw(self) -> [u8; 8] {
         self.0
     }
 
+    #[must_use]
     pub fn from_slice(data: &[u8]) -> Self {
         let mut buffer = [0; 8];
         data.iter().enumerate().for_each(|(i, &v)| buffer[i] = v);
@@ -1298,7 +1359,7 @@ impl From<points::RGB> for PointDataBuffer {
 }
 
 /// This trait is used to convert a byte slice to a primitive type.
-/// All PointField types are supported.
+/// All [`PointField`] types are supported.
 pub trait FromBytes: Default + Sized + Copy + GetFieldDatatype + Into<PointDataBuffer> {
     fn from_be_bytes(bytes: PointDataBuffer) -> Self;
     fn from_le_bytes(bytes: PointDataBuffer) -> Self;
@@ -1404,6 +1465,9 @@ mod tests {
     use super::Fields;
     use rpcl2_derive::Fields;
 
+    #[cfg(not(feature = "std"))]
+    use alloc::string::String;
+
     #[allow(dead_code)]
     #[derive(Fields)]
     struct TestStruct {
diff --git a/src/points.rs b/src/points.rs
index 68e31b9..b452bb4 100644
--- a/src/points.rs
+++ b/src/points.rs
@@ -4,6 +4,9 @@ use crate::{Fields, PointConvertible, RPCL2Point};
 #[cfg(feature = "derive")]
 use type_layout::TypeLayout;
 
+#[cfg(all(not(feature = "std"), feature = "derive"))]
+use alloc::vec::Vec;
+
 /// A packed RGB color encoding as used in ROS tools.
 #[derive(Clone, Copy)]
 #[repr(C)]
@@ -28,13 +31,13 @@ impl PartialEq for RGB {
 }
 
 impl core::fmt::Display for RGB {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         write!(f, "#{:02X}{:02X}{:02X}", self.r(), self.g(), self.b())
     }
 }
 
 impl core::fmt::Debug for RGB {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         f.debug_struct("RGB")
             .field("r", &self.r())
             .field("g", &self.g())
@@ -44,32 +47,39 @@ impl core::fmt::Debug for RGB {
 }
 
 impl RGB {
+    #[must_use]
     pub fn new(r: u8, g: u8, b: u8) -> Self {
         Self {
             unpacked: [b, g, r, 0],
         }
     }
 
+    #[must_use]
     pub fn new_from_packed_f32(packed: f32) -> Self {
         Self { packed }
     }
 
+    #[must_use]
     pub fn new_from_packed(packed: u32) -> Self {
         Self::new_from_packed_f32(f32::from_bits(packed))
     }
 
+    #[must_use]
     pub fn raw(&self) -> f32 {
         unsafe { self.packed }
     }
 
+    #[must_use]
     pub fn r(&self) -> u8 {
         unsafe { self.unpacked[2] }
     }
 
+    #[must_use]
     pub fn g(&self) -> u8 {
         unsafe { self.unpacked[1] }
     }
 
+    #[must_use]
     pub fn b(&self) -> u8 {
         unsafe { self.unpacked[0] }
     }
@@ -129,6 +139,7 @@ impl From<PointXYZ> for nalgebra::Point3<f32> {
 }
 
 impl PointXYZ {
+    #[must_use]
     pub fn new(x: f32, y: f32, z: f32) -> Self {
         Self { x, y, z }
     }
@@ -289,19 +300,23 @@ pub struct PointXYZRGB {
 }
 
 impl PointXYZRGB {
+    #[must_use]
     pub fn new(x: f32, y: f32, z: f32, r: u8, g: u8, b: u8) -> Self {
         let rgb = RGB::new(r, g, b);
         Self { x, y, z, rgb }
     }
 
+    #[must_use]
     pub fn r(&self) -> u8 {
         self.rgb.r()
     }
 
+    #[must_use]
     pub fn g(&self) -> u8 {
         self.rgb.g()
     }
 
+    #[must_use]
     pub fn b(&self) -> u8 {
         self.rgb.b()
     }
@@ -361,19 +376,23 @@ pub struct PointXYZRGBA {
 }
 
 impl PointXYZRGBA {
+    #[must_use]
     pub fn new(x: f32, y: f32, z: f32, r: u8, g: u8, b: u8, a: u8) -> Self {
         let rgb = RGB::new(r, g, b);
         Self { x, y, z, rgb, a }
     }
 
+    #[must_use]
     pub fn r(&self) -> u8 {
         self.rgb.r()
     }
 
+    #[must_use]
     pub fn g(&self) -> u8 {
         self.rgb.g()
     }
 
+    #[must_use]
     pub fn b(&self) -> u8 {
         self.rgb.b()
     }
@@ -436,6 +455,7 @@ pub struct PointXYZRGBNormal {
 }
 
 impl PointXYZRGBNormal {
+    #[must_use]
     pub fn new(
         x: f32,
         y: f32,
@@ -456,14 +476,17 @@ impl PointXYZRGBNormal {
         }
     }
 
+    #[must_use]
     pub fn r(&self) -> u8 {
         self.rgb.r()
     }
 
+    #[must_use]
     pub fn g(&self) -> u8 {
         self.rgb.g()
     }
 
+    #[must_use]
     pub fn b(&self) -> u8 {
         self.rgb.b()
     }
@@ -530,6 +553,7 @@ pub struct PointXYZINormal {
 }
 
 impl PointXYZINormal {
+    #[must_use]
     pub fn new(
         x: f32,
         y: f32,
@@ -613,6 +637,7 @@ unsafe impl Send for PointXYZRGBL {}
 unsafe impl Sync for PointXYZRGBL {}
 
 impl PointXYZRGBL {
+    #[must_use]
     pub fn new(x: f32, y: f32, z: f32, r: u8, g: u8, b: u8, label: u32) -> Self {
         let rgb = RGB::new(r, g, b);
         Self {
@@ -624,14 +649,17 @@ impl PointXYZRGBL {
         }
     }
 
+    #[must_use]
     pub fn r(&self) -> u8 {
         self.rgb.r()
     }
 
+    #[must_use]
     pub fn g(&self) -> u8 {
         self.rgb.g()
     }
 
+    #[must_use]
     pub fn b(&self) -> u8 {
         self.rgb.b()
     }
@@ -690,6 +718,7 @@ pub struct PointXYZNormal {
 }
 
 impl PointXYZNormal {
+    #[must_use]
     pub fn new(x: f32, y: f32, z: f32, normal_x: f32, normal_y: f32, normal_z: f32) -> Self {
         Self {
             x,
diff --git a/src/ros.rs b/src/ros.rs
index 0c24d5e..91fec8f 100644
--- a/src/ros.rs
+++ b/src/ros.rs
@@ -23,6 +23,9 @@
 //! }
 //! ```
 
+#[cfg(not(feature = "std"))]
+use alloc::string::String;
+
 /// [Time](https://docs.ros2.org/latest/api/builtin_interfaces/msg/Time.html) representation for ROS messages.
 #[derive(Clone, Debug, Default)]
 pub struct TimeMsg {

From 940c7b162308cdb593d03aa5bf683c7622b98a13 Mon Sep 17 00:00:00 2001
From: stelzo <stelzo@steado.de>
Date: Wed, 15 May 2024 21:27:10 +0200
Subject: [PATCH 2/5] add cfg docs

---
 Cargo.toml    |  2 ++
 src/lib.rs    | 23 ++++++++++++++++-------
 src/points.rs | 18 ++++++++++++++++++
 3 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 063fed5..6f18424 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -58,3 +58,5 @@ default = ["derive", "std"]
 [package.metadata.docs.rs]
 features = ["derive", "nalgebra", "rayon"]
 default-target = "x86_64-unknown-linux-gnu"
+rustdoc-args = ["--cfg", "docsrs"]
+
diff --git a/src/lib.rs b/src/lib.rs
index 443e9ad..4851259 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -53,12 +53,13 @@
 //! ```
 //!
 //! # Features
-//! - **r2r_msg** — Integration for the ROS2 library [r2r](https://github.com/sequenceplanner/r2r).
-//! - **(rclrs_msg)** — Integration for ROS2 [rclrs](https://github.com/ros2-rust/ros2_rust) but it needs this [workaround](https://github.com/stelzo/ros_pointcloud2?tab=readme-ov-file#rclrs-ros2_rust) instead of a feature flag.
-//! - **rosrust_msg** — Integration with the [rosrust](https://github.com/adnanademovic/rosrust) library for ROS1 message types.
-//! - **derive** (default) — Needed for the `_vec` functions and helpful custom point derive macros for the [`PointConvertible`] trait.
-//! - **rayon** — Parallel iterator support for `_par_iter` functions. [`PointCloud2Msg::try_from_par_iter`] additionally needs the 'derive' feature to be enabled.
-//! - **nalgebra** — When enabled, predefined points offer a `xyz()` getter returning `nalgebra::Point3`.
+//! - r2r_msg — Integration for the ROS2 library [r2r](https://github.com/sequenceplanner/r2r).
+//! - rosrust_msg — Integration with the [rosrust](https://github.com/adnanademovic/rosrust) library for ROS1 message types.
+//! - (rclrs_msg) — Integration for ROS2 [rclrs](https://github.com/ros2-rust/ros2_rust) but it currently needs [this workaround](https://github.com/stelzo/ros_pointcloud2?tab=readme-ov-file#rclrs-ros2_rust).
+//! - derive *(enabled by default)* — Enables the `_vec` functions and offers helpful custom point derive macros for the [`PointConvertible`] trait.
+//! - rayon — Parallel iterator support for `_par_iter` functions. [`PointCloud2Msg::try_from_par_iter`] additionally needs the 'derive' feature.
+//! - nalgebra — Predefined points offer a nalgebra typed getter for coordinates (e.g. [`points::PointXYZ::xyz`]).
+//! - std *(enabled by default)* — Use the standard library. Disable *all* features for `no_std` environments.
 //!
 //! # Custom Points
 //! Implement [`PointConvertible`] for your point with the `derive` feature or manually.
@@ -126,6 +127,8 @@
 //! }
 //! ```
 #![crate_type = "lib"]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![doc(html_root_url = "https://docs.rs/ros_pointcloud2/1.0.0-rc.1")]
 #![warn(clippy::print_stderr)]
 #![warn(clippy::print_stdout)]
 #![warn(clippy::unwrap_used)]
@@ -551,6 +554,7 @@ impl PointCloud2Msg {
 
     /// Create a PointCloud2Msg from a parallel iterator. Requires the `rayon` and `derive` feature to be enabled.
     #[cfg(all(feature = "rayon", feature = "derive"))]
+    #[cfg_attr(docsrs, doc(cfg(all(feature = "rayon", feature = "derive"))))]
     pub fn try_from_par_iter<const N: usize, C>(
         iterable: impl rayon::iter::ParallelIterator<Item = C>,
     ) -> Result<Self, MsgConversionError>
@@ -578,6 +582,7 @@ impl PointCloud2Msg {
     /// # Errors
     /// Returns an error if the byte buffer does not match the expected layout or the message contains other discrepancies.
     #[cfg(feature = "derive")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "derive")))]
     pub fn try_from_vec<const N: usize, C>(vec: Vec<C>) -> Result<Self, MsgConversionError>
     where
         C: PointConvertible<N>,
@@ -666,6 +671,7 @@ impl PointCloud2Msg {
     /// # Errors
     /// Returns an error if the byte buffer does not match the expected layout or the message contains other discrepancies.
     #[cfg(feature = "derive")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "derive")))]
     pub fn try_into_vec<const N: usize, C>(self) -> Result<Vec<C>, MsgConversionError>
     where
         C: PointConvertible<N>,
@@ -746,6 +752,7 @@ impl PointCloud2Msg {
     /// let cloud_points_out = msg_out.try_into_par_iter().unwrap().collect::<Vec<PointXYZ>>();
     /// assert_eq!(2, cloud_points_out.len());
     /// ```
+    #[cfg_attr(docsrs, doc(cfg(feature = "rayon")))]
     #[cfg(feature = "rayon")]
     pub fn try_into_par_iter<const N: usize, C>(
         self,
@@ -828,6 +835,7 @@ impl<const N: usize> From<[PointData; N]> for RPCL2Point<N> {
 ///
 /// impl PointConvertible<4> for MyPointXYZI {}
 /// ```
+#[cfg_attr(docsrs, doc(cfg(not(feature = "derive"))))]
 #[cfg(not(feature = "derive"))]
 pub trait PointConvertible<const N: usize>:
     From<RPCL2Point<N>> + Into<RPCL2Point<N>> + Fields<N> + Clone + Default
@@ -889,6 +897,7 @@ pub trait PointConvertible<const N: usize>:
 ///
 /// impl PointConvertible<4> for MyPointXYZI {}
 /// ```
+#[cfg_attr(docsrs, doc(cfg(feature = "derive")))]
 #[cfg(feature = "derive")]
 pub trait PointConvertible<const N: usize>:
     type_layout::TypeLayout + From<RPCL2Point<N>> + Into<RPCL2Point<N>> + Fields<N> + Default
@@ -1359,7 +1368,7 @@ impl From<points::RGB> for PointDataBuffer {
 }
 
 /// This trait is used to convert a byte slice to a primitive type.
-/// All [`PointField`] types are supported.
+/// All [`ros::PointFieldMsg`] types are supported.
 pub trait FromBytes: Default + Sized + Copy + GetFieldDatatype + Into<PointDataBuffer> {
     fn from_be_bytes(bytes: PointDataBuffer) -> Self;
     fn from_le_bytes(bytes: PointDataBuffer) -> Self;
diff --git a/src/points.rs b/src/points.rs
index b452bb4..d6ffa6b 100644
--- a/src/points.rs
+++ b/src/points.rs
@@ -144,7 +144,9 @@ impl PointXYZ {
         Self { x, y, z }
     }
 
+    /// Get the coordinates as a nalgebra Point3.
     #[cfg(feature = "nalgebra")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "nalgebra")))]
     pub fn xyz(&self) -> nalgebra::Point3<f32> {
         nalgebra::Point3::new(self.x, self.y, self.z)
     }
@@ -190,7 +192,9 @@ impl PointXYZI {
         Self { x, y, z, intensity }
     }
 
+    /// Get the coordinates as a nalgebra Point3.
     #[cfg(feature = "nalgebra")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "nalgebra")))]
     pub fn xyz(&self) -> nalgebra::Point3<f32> {
         nalgebra::Point3::new(self.x, self.y, self.z)
     }
@@ -247,7 +251,9 @@ impl PointXYZL {
         Self { x, y, z, label }
     }
 
+    /// Get the coordinates as a nalgebra Point3.
     #[cfg(feature = "nalgebra")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "nalgebra")))]
     pub fn xyz(&self) -> nalgebra::Point3<f32> {
         nalgebra::Point3::new(self.x, self.y, self.z)
     }
@@ -321,7 +327,9 @@ impl PointXYZRGB {
         self.rgb.b()
     }
 
+    /// Get the coordinates as a nalgebra Point3.
     #[cfg(feature = "nalgebra")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "nalgebra")))]
     pub fn xyz(&self) -> nalgebra::Point3<f32> {
         nalgebra::Point3::new(self.x, self.y, self.z)
     }
@@ -397,7 +405,9 @@ impl PointXYZRGBA {
         self.rgb.b()
     }
 
+    /// Get the coordinates as a nalgebra Point3.
     #[cfg(feature = "nalgebra")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "nalgebra")))]
     pub fn xyz(&self) -> nalgebra::Point3<f32> {
         nalgebra::Point3::new(self.x, self.y, self.z)
     }
@@ -491,7 +501,9 @@ impl PointXYZRGBNormal {
         self.rgb.b()
     }
 
+    /// Get the coordinates as a nalgebra Point3.
     #[cfg(feature = "nalgebra")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "nalgebra")))]
     pub fn xyz(&self) -> nalgebra::Point3<f32> {
         nalgebra::Point3::new(self.x, self.y, self.z)
     }
@@ -574,7 +586,9 @@ impl PointXYZINormal {
         }
     }
 
+    /// Get the coordinates as a nalgebra Point3.
     #[cfg(feature = "nalgebra")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "nalgebra")))]
     pub fn xyz(&self) -> nalgebra::Point3<f32> {
         nalgebra::Point3::new(self.x, self.y, self.z)
     }
@@ -664,7 +678,9 @@ impl PointXYZRGBL {
         self.rgb.b()
     }
 
+    /// Get the coordinates as a nalgebra Point3.
     #[cfg(feature = "nalgebra")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "nalgebra")))]
     pub fn xyz(&self) -> nalgebra::Point3<f32> {
         nalgebra::Point3::new(self.x, self.y, self.z)
     }
@@ -730,7 +746,9 @@ impl PointXYZNormal {
         }
     }
 
+    /// Get the coordinates as a nalgebra Point3.
     #[cfg(feature = "nalgebra")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "nalgebra")))]
     pub fn xyz(&self) -> nalgebra::Point3<f32> {
         nalgebra::Point3::new(self.x, self.y, self.z)
     }

From 806536762e24e394e31c860b332d6b940f7dd727 Mon Sep 17 00:00:00 2001
From: stelzo <stelzo@steado.de>
Date: Wed, 15 May 2024 21:46:00 +0200
Subject: [PATCH 3/5] move to dual license, inline crate for syn2

---
 Cargo.toml                                |   4 +-
 LICENSE-APACHE                            | 201 +++++++++++++++++++++
 LICENSE => LICENSE-MIT                    |   2 +-
 README.md                                 |  14 +-
 type-layout/Cargo.toml                    |  27 +++
 type-layout/LICENSE-APACHE                | 201 +++++++++++++++++++++
 type-layout/LICENSE-MIT                   |  19 ++
 type-layout/src/lib.rs                    | 204 ++++++++++++++++++++++
 type-layout/type-layout-derive/Cargo.toml |  18 ++
 type-layout/type-layout-derive/src/lib.rs |  93 ++++++++++
 10 files changed, 775 insertions(+), 8 deletions(-)
 create mode 100644 LICENSE-APACHE
 rename LICENSE => LICENSE-MIT (95%)
 create mode 100644 type-layout/Cargo.toml
 create mode 100644 type-layout/LICENSE-APACHE
 create mode 100644 type-layout/LICENSE-MIT
 create mode 100644 type-layout/src/lib.rs
 create mode 100644 type-layout/type-layout-derive/Cargo.toml
 create mode 100644 type-layout/type-layout-derive/src/lib.rs

diff --git a/Cargo.toml b/Cargo.toml
index 6f18424..5f9b847 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,7 @@ edition = "2021"
 authors = ["Christopher Sieh <stelzo@steado.de>"]
 description = "Customizable conversions for working with sensor_msgs/PointCloud2."
 repository = "https://github.com/stelzo/ros_pointcloud2"
-license = "MIT"
+license = "MIT OR Apache-2.0"
 keywords = ["ros", "pointcloud2", "pointcloud", "message"]
 categories = [
     "science::robotics",
@@ -35,7 +35,7 @@ r2r = { version = "0.8.4", optional = true }
 rayon = { version = "1", optional = true }
 nalgebra = { version = "0", optional = true }
 rpcl2_derive = { path = "./rpcl2_derive", optional = true }
-type-layout = { git = "https://github.com/stelzo/type-layout", branch = "syn2", optional = true }
+type-layout = { path = "type-layout", optional = true }
 
 [dev-dependencies]
 rand = "0.8"
diff --git a/LICENSE-APACHE b/LICENSE-APACHE
new file mode 100644
index 0000000..d42ecff
--- /dev/null
+++ b/LICENSE-APACHE
@@ -0,0 +1,201 @@
+i                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
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+      subsequently incorporated within the Work.
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+   2. Grant of Copyright License. Subject to the terms and conditions of
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+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/LICENSE b/LICENSE-MIT
similarity index 95%
rename from LICENSE
rename to LICENSE-MIT
index 0ceb3c6..1bcdf6f 100644
--- a/LICENSE
+++ b/LICENSE-MIT
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2023 Christopher Sieh
+Copyright (c) 2024 Christopher Sieh
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/README.md b/README.md
index ae1d811..a2ce41c 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,5 @@
-## !! Note !!
-
-This library is currently in development for v1.0.0, for the documentation of v0.4.0 on crates.io, visit the [docs](https://docs.rs/ros_pointcloud2/0.4.0/ros_pointcloud2/).
+> [!NOTE]  
+> This library is currently in development for v1. For the documentation of the current live version v0.4, visit the [docs](https://docs.rs/ros_pointcloud2/0.4.0/ros_pointcloud2/).
 
 <p align="center">
   <h3 align="center">ROS PointCloud2</h3>
@@ -95,10 +94,15 @@ The results are measured on an Intel i7-14700 with benchmarks from [this reposit
 
 For minimizing the conversion overhead in general, always use the functions that best fit your use case.
 
-## `#[no_std]`
+## `no_std` Environments
 
 The `_iter` conversions are compatible with `#[no_std]` environments when an allocator is provided. This is due to the fact that names for point fields do not have a maximum length, and PointCloud2 data vectors can have arbitrary sizes. Use `default-features = false` to disable std for this crate.
 
 ## License
 
-[MIT](https://choosealicense.com/licenses/mit/)
+Dual licensed under your choice of either of:
+
+- [Apache License, Version 2.0](https://www.apache.org/licenses/LICENSE-2.0)
+- [MIT License](https://opensource.org/licenses/MIT)
+
+at your option.
diff --git a/type-layout/Cargo.toml b/type-layout/Cargo.toml
new file mode 100644
index 0000000..c4d7fc7
--- /dev/null
+++ b/type-layout/Cargo.toml
@@ -0,0 +1,27 @@
+[package]
+name = "type-layout"
+description = "Derivable trait to view the layout of a struct, useful for debugging."
+version = "0.2.0"
+edition = "2018"
+authors = ["Lucien Greathouse <me@lpghatguy.com>"]
+documentation = "https://docs.rs/type-layout"
+homepage = "https://github.com/LPGhatguy/type-layout"
+repository = "https://github.com/LPGhatguy/type-layout"
+readme = "README.md"
+keywords = ["layout", "struct", "type"]
+license = "MIT OR Apache-2.0"
+rust-version = "1.60.0"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[features]
+serde1 = ["serde"]
+
+[workspace]
+members = ["type-layout-derive", "try-crate"]
+
+[dependencies]
+type-layout-derive = { version = "0.2.0", path = "type-layout-derive" }
+
+memoffset = "0.5"
+serde = { version = "1.0.116", features = ["derive"], optional = true }
diff --git a/type-layout/LICENSE-APACHE b/type-layout/LICENSE-APACHE
new file mode 100644
index 0000000..d42ecff
--- /dev/null
+++ b/type-layout/LICENSE-APACHE
@@ -0,0 +1,201 @@
+i                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/type-layout/LICENSE-MIT b/type-layout/LICENSE-MIT
new file mode 100644
index 0000000..32c2307
--- /dev/null
+++ b/type-layout/LICENSE-MIT
@@ -0,0 +1,19 @@
+Copyright (c) 2020 Lucien Greathouse
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
\ No newline at end of file
diff --git a/type-layout/src/lib.rs b/type-layout/src/lib.rs
new file mode 100644
index 0000000..af8d7b3
--- /dev/null
+++ b/type-layout/src/lib.rs
@@ -0,0 +1,204 @@
+/*!
+[![GitHub CI Status](https://github.com/LPGhatguy/type-layout/workflows/CI/badge.svg)](https://github.com/LPGhatguy/type-layout/actions)
+[![type-layout on crates.io](https://img.shields.io/crates/v/type-layout.svg)](https://crates.io/crates/type-layout)
+[![type-layout docs](https://img.shields.io/badge/docs-docs.rs-orange.svg)](https://docs.rs/type-layout)
+
+type-layout is a type layout debugging aid, providing a `#[derive]`able trait
+that reports:
+- The type's name, size, and minimum alignment
+- Each field's name, type, offset, and size
+- Padding due to alignment requirements
+
+**type-layout currently only functions on structs with named fields.** This is a
+temporary limitation.
+
+## Examples
+
+The layout of types is only defined if they're `#[repr(C)]`. This crate works on
+non-`#[repr(C)]` types, but their layout is unpredictable.
+
+```rust
+use type_layout::TypeLayout;
+
+#[derive(TypeLayout)]
+#[repr(C)]
+struct Foo {
+    a: u8,
+    b: u32,
+}
+
+println!("{}", Foo::type_layout());
+// prints:
+// Foo (size 8, alignment 4)
+// | Offset | Name      | Size |
+// | ------ | --------- | ---- |
+// | 0      | a         | 1    |
+// | 1      | [padding] | 3    |
+// | 4      | b         | 4    |
+```
+
+Over-aligned types have trailing padding, which can be a source of bugs in some
+FFI scenarios:
+
+```rust
+use type_layout::TypeLayout;
+
+#[derive(TypeLayout)]
+#[repr(C, align(128))]
+struct OverAligned {
+    value: u8,
+}
+
+println!("{}", OverAligned::type_layout());
+// prints:
+// OverAligned (size 128, alignment 128)
+// | Offset | Name      | Size |
+// | ------ | --------- | ---- |
+// | 0      | value     | 1    |
+// | 1      | [padding] | 127  |
+```
+
+## Minimum Supported Rust Version (MSRV)
+
+type-layout supports Rust 1.34.1 and newer. Until type-layout reaches 1.0,
+changes to the MSRV will require major version bumps. After 1.0, MSRV changes
+will only require minor version bumps, but will need significant justification.
+*/
+
+use std::borrow::Cow;
+use std::fmt::{self, Display};
+use std::str;
+
+pub use type_layout_derive::TypeLayout;
+
+#[doc(hidden)]
+pub use memoffset;
+
+pub trait TypeLayout {
+    fn type_layout() -> TypeLayoutInfo;
+}
+
+#[derive(Debug)]
+#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]
+pub struct TypeLayoutInfo {
+    pub name: Cow<'static, str>,
+    pub size: usize,
+    pub alignment: usize,
+    pub fields: Vec<Field>,
+}
+
+#[derive(Debug)]
+#[cfg_attr(feature = "serde1", derive(serde::Serialize, serde::Deserialize))]
+pub enum Field {
+    Field {
+        name: Cow<'static, str>,
+        ty: Cow<'static, str>,
+        size: usize,
+    },
+    Padding {
+        size: usize,
+    },
+}
+
+impl fmt::Display for TypeLayoutInfo {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        writeln!(
+            formatter,
+            "{} (size {}, alignment {})",
+            self.name, self.size, self.alignment
+        )?;
+
+        let longest_name = self
+            .fields
+            .iter()
+            .map(|field| match field {
+                Field::Field { name, .. } => name.len(),
+                Field::Padding { .. } => "[padding]".len(),
+            })
+            .max()
+            .unwrap_or(1);
+
+        let widths = RowWidths {
+            offset: "Offset".len(),
+            name: longest_name,
+            size: "Size".len(),
+        };
+
+        write_row(
+            formatter,
+            widths,
+            Row {
+                offset: "Offset",
+                name: "Name",
+                size: "Size",
+            },
+        )?;
+
+        write_row(
+            formatter,
+            widths,
+            Row {
+                offset: "------",
+                name: str::repeat("-", longest_name),
+                size: "----",
+            },
+        )?;
+
+        let mut offset = 0;
+
+        for field in &self.fields {
+            match field {
+                Field::Field { name, size, .. } => {
+                    write_row(formatter, widths, Row { offset, name, size })?;
+
+                    offset += size;
+                }
+                Field::Padding { size } => {
+                    write_row(
+                        formatter,
+                        widths,
+                        Row {
+                            offset,
+                            name: "[padding]",
+                            size,
+                        },
+                    )?;
+
+                    offset += size;
+                }
+            }
+        }
+
+        Ok(())
+    }
+}
+
+#[derive(Clone, Copy)]
+struct RowWidths {
+    offset: usize,
+    name: usize,
+    size: usize,
+}
+
+struct Row<O, N, S> {
+    offset: O,
+    name: N,
+    size: S,
+}
+
+fn write_row<O: Display, N: Display, S: Display>(
+    formatter: &mut fmt::Formatter,
+    widths: RowWidths,
+    row: Row<O, N, S>,
+) -> fmt::Result {
+    writeln!(
+        formatter,
+        "| {:<offset_width$} | {:<name_width$} | {:<size_width$} |",
+        row.offset,
+        row.name,
+        row.size,
+        offset_width = widths.offset,
+        name_width = widths.name,
+        size_width = widths.size
+    )
+}
diff --git a/type-layout/type-layout-derive/Cargo.toml b/type-layout/type-layout-derive/Cargo.toml
new file mode 100644
index 0000000..1c5ebd1
--- /dev/null
+++ b/type-layout/type-layout-derive/Cargo.toml
@@ -0,0 +1,18 @@
+[package]
+name = "type-layout-derive"
+description = "Derive macro implementation for type-layout crate"
+version = "0.2.0"
+edition = "2018"
+authors = ["Lucien Greathouse <me@lpghatguy.com>"]
+homepage = "https://github.com/LPGhatguy/type-layout"
+license = "MIT OR Apache-2.0"
+
+[lib]
+proc-macro = true
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+syn = "2"
+quote = "1.0.7"
+proc-macro2 = "1.0.21"
diff --git a/type-layout/type-layout-derive/src/lib.rs b/type-layout/type-layout-derive/src/lib.rs
new file mode 100644
index 0000000..a031c6e
--- /dev/null
+++ b/type-layout/type-layout-derive/src/lib.rs
@@ -0,0 +1,93 @@
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+
+use proc_macro2::{Ident, Literal};
+use quote::{quote, quote_spanned, ToTokens};
+use syn::{parse_macro_input, spanned::Spanned, Data, DeriveInput, Fields};
+
+#[proc_macro_derive(TypeLayout)]
+pub fn derive_type_layout(input: TokenStream) -> TokenStream {
+    // Parse the input tokens into a syntax tree
+    let input = parse_macro_input!(input as DeriveInput);
+
+    // Used in the quasi-quotation below as `#name`.
+    let name = input.ident;
+    let name_str = Literal::string(&name.to_string());
+
+    let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
+    let layout = layout_of_type(&name, &input.data);
+
+    // Build the output, possibly using quasi-quotation
+    let expanded = quote! {
+        impl #impl_generics ::type_layout::TypeLayout for #name #ty_generics #where_clause {
+            fn type_layout() -> ::type_layout::TypeLayoutInfo {
+                let mut last_field_end = 0;
+                let mut fields = Vec::new();
+
+                #layout
+
+                ::type_layout::TypeLayoutInfo {
+                    name: ::std::borrow::Cow::Borrowed(#name_str),
+                    size: std::mem::size_of::<#name>(),
+                    alignment: ::std::mem::align_of::<#name>(),
+                    fields,
+                }
+            }
+        }
+    };
+
+    // Hand the output tokens back to the compiler
+    TokenStream::from(expanded)
+}
+
+fn layout_of_type(struct_name: &Ident, data: &Data) -> proc_macro2::TokenStream {
+    match data {
+        Data::Struct(data) => match &data.fields {
+            Fields::Named(fields) => {
+                let values = fields.named.iter().map(|field| {
+                    let field_name = field.ident.as_ref().unwrap();
+                    let field_name_str = Literal::string(&field_name.to_string());
+                    let field_ty = &field.ty;
+                    let field_ty_str = Literal::string(&field_ty.to_token_stream().to_string());
+
+                    quote_spanned! { field.span() =>
+                        #[allow(unused_assignments)]
+                        {
+                            let size = ::std::mem::size_of::<#field_ty>();
+                            let offset = ::type_layout::memoffset::offset_of!(#struct_name, #field_name);
+
+                            if offset > last_field_end {
+                                fields.push(::type_layout::Field::Padding {
+                                    size: offset - last_field_end
+                                });
+                            }
+
+                            fields.push(::type_layout::Field::Field {
+                                name: ::std::borrow::Cow::Borrowed(#field_name_str),
+                                ty: ::std::borrow::Cow::Borrowed(#field_ty_str),
+                                size,
+                            });
+
+                            last_field_end = offset + size;
+                        }
+                    }
+                });
+
+                quote! {
+                    #(#values)*
+
+                    let struct_size = ::std::mem::size_of::<#struct_name>();
+                    if struct_size > last_field_end {
+                        fields.push(::type_layout::Field::Padding {
+                            size: struct_size - last_field_end,
+                        });
+                    }
+                }
+            }
+            Fields::Unnamed(_) => unimplemented!(),
+            Fields::Unit => unimplemented!(),
+        },
+        Data::Enum(_) | Data::Union(_) => unimplemented!("type-layout only supports structs"),
+    }
+}

From d67518abff7a9746c75d0f40326749ab19e327f3 Mon Sep 17 00:00:00 2001
From: stelzo <stelzo@steado.de>
Date: Wed, 15 May 2024 22:02:39 +0200
Subject: [PATCH 4/5] specify licensing

---
 README.md | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index a2ce41c..3e21edf 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 > [!NOTE]  
-> This library is currently in development for v1. For the documentation of the current live version v0.4, visit the [docs](https://docs.rs/ros_pointcloud2/0.4.0/ros_pointcloud2/).
+> This library is currently in preparation for v1. For the documentation of the current crates.io v0.4, visit the [docs](https://docs.rs/ros_pointcloud2/0.4.0/ros_pointcloud2/).
 
 <p align="center">
   <h3 align="center">ROS PointCloud2</h3>
@@ -10,7 +10,7 @@
 
 ros_pointcloud2 uses its own type for the message `PointCloud2Msg` to keep the library framework agnostic. ROS1 and ROS2 are supported with feature flags.
 
-Get started with the example below, check out the other use cases in the `examples` folder or see the [Documentation](https://docs.rs/ros_pointcloud2/1.0.0/ros_pointcloud2/) for a complete guide.
+Get started with the example below, check out the other use cases in the `examples` folder or see the [Documentation](https://docs.rs/ros_pointcloud2/1.0.0-rc.1/) for a complete guide.
 
 ## Quickstart
 
@@ -100,9 +100,17 @@ The `_iter` conversions are compatible with `#[no_std]` environments when an all
 
 ## License
 
-Dual licensed under your choice of either of:
+Licensed under either of
 
-- [Apache License, Version 2.0](https://www.apache.org/licenses/LICENSE-2.0)
-- [MIT License](https://opensource.org/licenses/MIT)
+- Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+- MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 
 at your option.
+
+### type-layout
+For compatibility reasons, a patched version of `type-layout` is included in this repository. The original crate can be found [here](https://crates.io/crates/type-layout). After the patch is applied on the original `type-layout` crate ([PR](https://github.com/LPGhatguy/type-layout/pull/9)), the local dependency will be changed to the original crate.
+
+`type-layout` is licensed under MIT or Apache-2.0 and Copyright by Lucien Greathouse. The changes are highlighted in the diff of the PR.
+
+### Contribution
+Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

From acab42d2035d2b6597222e06b94838d13defbc08 Mon Sep 17 00:00:00 2001
From: stelzo <stelzo@steado.de>
Date: Wed, 15 May 2024 22:56:55 +0200
Subject: [PATCH 5/5] prepare version

---
 .github/workflows/tests.yml |  2 +-
 Cargo.toml                  |  4 ++--
 README.md                   |  8 ++++----
 src/iterator.rs             | 14 +++++---------
 src/lib.rs                  |  9 ++-------
 src/points.rs               |  2 +-
 src/ros.rs                  |  1 -
 7 files changed, 15 insertions(+), 25 deletions(-)

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index c15a23f..e9ca8b9 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -23,6 +23,6 @@ jobs:
           rustc --version
           cargo --version
       - name: Linting
-        run: cargo clippy --all-targets -- -D warnings
+        run: cargo clippy --all-targets --features derive,nalgebra,rayon -- -D warnings
       - name: Tests
         run: cargo test --features derive,nalgebra,rayon
diff --git a/Cargo.toml b/Cargo.toml
index 5f9b847..9c21c67 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ros_pointcloud2"
-version = "1.0.0-rc.1"
+version = "0.5.0-rc.1"
 edition = "2021"
 authors = ["Christopher Sieh <stelzo@steado.de>"]
 description = "Customizable conversions for working with sensor_msgs/PointCloud2."
@@ -53,7 +53,7 @@ derive = ["dep:rpcl2_derive", "dep:type-layout"]
 nalgebra = ["dep:nalgebra"]
 std = []
 
-default = ["derive", "std"]
+default = ["std", "derive"]
 
 [package.metadata.docs.rs]
 features = ["derive", "nalgebra", "rayon"]
diff --git a/README.md b/README.md
index 3e21edf..d1a6fd9 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 > [!NOTE]  
-> This library is currently in preparation for v1. For the documentation of the current crates.io v0.4, visit the [docs](https://docs.rs/ros_pointcloud2/0.4.0/ros_pointcloud2/).
+> This library is currently in preparation for v0.5 with many breaking changes. For the documentation of the current crates.io v0.4.0, visit the [docs](https://docs.rs/ros_pointcloud2/0.4.0/ros_pointcloud2/). Since rclrs still needs a workaround, the version number must be changed to your desired version which supports rclrs (currently only v0.4.0) — regardless of the version number shown in this Readme.
 
 <p align="center">
   <h3 align="center">ROS PointCloud2</h3>
@@ -10,7 +10,7 @@
 
 ros_pointcloud2 uses its own type for the message `PointCloud2Msg` to keep the library framework agnostic. ROS1 and ROS2 are supported with feature flags.
 
-Get started with the example below, check out the other use cases in the `examples` folder or see the [Documentation](https://docs.rs/ros_pointcloud2/1.0.0-rc.1/) for a complete guide.
+Get started with the example below, check out the other use cases in the `examples` folder or see the [Documentation](https://docs.rs/ros_pointcloud2/0.5.0-rc.1/) for a complete guide.
 
 ## Quickstart
 
@@ -71,7 +71,7 @@ Features do not work properly with `rcrls` because the messages are linked exter
 
 ```toml
 [dependencies]
-ros_pointcloud2 = { git = "https://github.com/stelzo/ros_pointcloud2", tag = "v0.4.0_rclrs" }
+ros_pointcloud2 = { git = "https://github.com/stelzo/ros_pointcloud2", tag = "v0.5.0-rc.1_rclrs" }
 ```
 
 Also, indicate the following dependencies to your linker inside the `package.xml` of your package.
@@ -96,7 +96,7 @@ For minimizing the conversion overhead in general, always use the functions that
 
 ## `no_std` Environments
 
-The `_iter` conversions are compatible with `#[no_std]` environments when an allocator is provided. This is due to the fact that names for point fields do not have a maximum length, and PointCloud2 data vectors can have arbitrary sizes. Use `default-features = false` to disable std for this crate.
+The `_iter` conversions are compatible with `#[no_std]` environments if an allocator is provided. This is due to the fact that names for point fields do not have a maximum length, and PointCloud2 data vectors can have arbitrary sizes. Use `default-features = false` to disable std for this crate.
 
 ## License
 
diff --git a/src/iterator.rs b/src/iterator.rs
index 938d256..7e6b7c7 100644
--- a/src/iterator.rs
+++ b/src/iterator.rs
@@ -4,14 +4,9 @@ use crate::{
     RPCL2Point,
 };
 
-#[cfg(not(feature = "std"))]
-use alloc::string::String;
-
-#[cfg(not(feature = "std"))]
-use alloc::vec::Vec;
-
-#[cfg(not(feature = "std"))]
 use alloc::borrow::ToOwned;
+use alloc::string::String;
+use alloc::vec::Vec;
 
 /// The PointCloudIterator provides a an iterator abstraction of the [`PointCloud2Msg`].
 ///
@@ -166,7 +161,7 @@ where
 
 struct ByteBufferView<const N: usize> {
     #[cfg(feature = "rayon")]
-    data: std::sync::Arc<[u8]>,
+    data: alloc::sync::Arc<[u8]>,
     #[cfg(not(feature = "rayon"))]
     data: Vec<u8>,
     start_point_idx: usize,
@@ -189,7 +184,7 @@ impl<const N: usize> ByteBufferView<N> {
     ) -> Self {
         Self {
             #[cfg(feature = "rayon")]
-            data: std::sync::Arc::<[u8]>::from(data),
+            data: alloc::sync::Arc::<[u8]>::from(data),
             #[cfg(not(feature = "rayon"))]
             data,
             start_point_idx,
@@ -380,6 +375,7 @@ where
 
 #[cfg(feature = "rayon")]
 mod test {
+    #![allow(clippy::unwrap_used)]
 
     #[test]
     fn test_double_ended_iter() {
diff --git a/src/lib.rs b/src/lib.rs
index 4851259..a3475af 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -128,7 +128,7 @@
 //! ```
 #![crate_type = "lib"]
 #![cfg_attr(docsrs, feature(doc_cfg))]
-#![doc(html_root_url = "https://docs.rs/ros_pointcloud2/1.0.0-rc.1")]
+#![doc(html_root_url = "https://docs.rs/ros_pointcloud2/0.5.0-rc.1")]
 #![warn(clippy::print_stderr)]
 #![warn(clippy::print_stdout)]
 #![warn(clippy::unwrap_used)]
@@ -148,16 +148,12 @@ pub mod iterator;
 
 use crate::ros::{HeaderMsg, PointFieldMsg};
 
+#[cfg(feature = "derive")]
 use core::str::FromStr;
 
-#[cfg(not(feature = "std"))]
 #[macro_use]
 extern crate alloc;
-
-#[cfg(not(feature = "std"))]
 use alloc::string::String;
-
-#[cfg(not(feature = "std"))]
 use alloc::vec::Vec;
 
 /// All errors that can occur while converting to or from the message type.
@@ -1474,7 +1470,6 @@ mod tests {
     use super::Fields;
     use rpcl2_derive::Fields;
 
-    #[cfg(not(feature = "std"))]
     use alloc::string::String;
 
     #[allow(dead_code)]
diff --git a/src/points.rs b/src/points.rs
index d6ffa6b..9c8d0af 100644
--- a/src/points.rs
+++ b/src/points.rs
@@ -4,7 +4,7 @@ use crate::{Fields, PointConvertible, RPCL2Point};
 #[cfg(feature = "derive")]
 use type_layout::TypeLayout;
 
-#[cfg(all(not(feature = "std"), feature = "derive"))]
+#[cfg(feature = "derive")]
 use alloc::vec::Vec;
 
 /// A packed RGB color encoding as used in ROS tools.
diff --git a/src/ros.rs b/src/ros.rs
index 91fec8f..ccdc8cc 100644
--- a/src/ros.rs
+++ b/src/ros.rs
@@ -23,7 +23,6 @@
 //! }
 //! ```
 
-#[cfg(not(feature = "std"))]
 use alloc::string::String;
 
 /// [Time](https://docs.ros2.org/latest/api/builtin_interfaces/msg/Time.html) representation for ROS messages.