Merge pull request 'Add Error impls if std feature is used' (#2) from add_error_impls_for_std_feature into main

Reviewed-on: #2

CHANGELOG.md

@@ -11,7 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ## Changed
 
 - `serde` support is now optional and behind the `serde` feature.
-- `PusTcSecondaryHeaderT` trait renamed to `GenericPusTcSecondaryHeader`
+- `PusTcSecondaryHeaderT` trait renamed to `GenericPusTcSecondaryHeader`.
 - `PusTmSecondaryHeaderT` trait renamed to `GenericPusTmSecondaryHeader`.
 - `SpHeader`: Former `tc` and `tm` methods now named `tc_unseg` and `tm_unseg`.
   Former `new` method now called `new_from_single_fields`.
@@ -20,6 +20,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Added
 
+- Added `std::error::Error` implementation for all error enumerations if the `std` feature
+  is enabled.
+- ACII timestamps as specified in CCSDS 301.0-B-4.
 - Added MSRV in `Cargo.toml` with the `rust-version` field set to Rust 1.60.
 - ACII timestamps as specified in CCSDS 301.0-B-4
 - `serde` `Serialize` and `Deserialize` added to all types.

src/ecss.rs

@@ -1,11 +1,13 @@
 //! Common definitions and helpers required to create PUS TMTC packets according to
 //! [ECSS-E-ST-70-41C](https://ecss.nl/standard/ecss-e-st-70-41c-space-engineering-telemetry-and-telecommand-packet-utilization-15-april-2016/)
 use crate::{ByteConversionError, CcsdsPacket, SizeMissmatch};
-use core::fmt::Debug;
+use core::fmt::{Debug, Display, Formatter};
 use core::mem::size_of;
 use crc::{Crc, CRC_16_IBM_3740};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
+#[cfg(feature = "std")]
+use std::error::Error;
 
 pub type CrcType = u16;
 
@@ -65,6 +67,45 @@ pub enum PusError {
     ByteConversionError(ByteConversionError),
 }
 
+impl Display for PusError {
+    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
+        match self {
+            PusError::VersionNotSupported(v) => {
+                write!(f, "PUS version {:?} not supported", v)
+            }
+            PusError::IncorrectCrc(crc) => {
+                write!(f, "crc16 {:#04x} is incorrect", crc)
+            }
+            PusError::RawDataTooShort(size) => {
+                write!(
+                    f,
+                    "deserialization error, provided raw data with size {} too short",
+                    size
+                )
+            }
+            PusError::NoRawData => {
+                write!(f, "no raw data provided")
+            }
+            PusError::CrcCalculationMissing => {
+                write!(f, "crc16 was not calculated")
+            }
+            PusError::ByteConversionError(e) => {
+                write!(f, "low level byte conversion error: {}", e)
+            }
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl Error for PusError {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        if let PusError::ByteConversionError(e) = self {
+            return Some(e);
+        }
+        None
+    }
+}
+
 impl From<ByteConversionError> for PusError {
     fn from(e: ByteConversionError) -> Self {
         PusError::ByteConversionError(e)

src/lib.rs

@@ -55,7 +55,10 @@ extern crate alloc;
 extern crate std;
 
 use crate::ecss::CCSDS_HEADER_LEN;
+use core::fmt::{Display, Formatter};
 use delegate::delegate;
+#[cfg(feature = "std")]
+use std::error::Error;
 
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
@@ -87,6 +90,36 @@ pub enum ByteConversionError {
     ZeroCopyFromError,
 }
 
+impl Display for ByteConversionError {
+    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
+        match self {
+            ByteConversionError::ToSliceTooSmall(missmatch) => {
+                write!(
+                    f,
+                    "target slice with size {} is too small, expected size of at least {}",
+                    missmatch.found, missmatch.expected
+                )
+            }
+            ByteConversionError::FromSliceTooSmall(missmatch) => {
+                write!(
+                    f,
+                    "source slice with size {} too small, expected at least {} bytes",
+                    missmatch.found, missmatch.expected
+                )
+            }
+            ByteConversionError::ZeroCopyToError => {
+                write!(f, "zerocopy serialization error")
+            }
+            ByteConversionError::ZeroCopyFromError => {
+                write!(f, "zerocopy deserialization error")
+            }
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl Error for ByteConversionError {}
+
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum PacketType {