Merge pull request aeron-io#940 from GreenPenguino/rust-decoder-copy-clone

[Rust] Add derive Copy Clone traits for decoders

Author: vyazelenko

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/rust/LibRsDef.java

@@ -149,7 +149,7 @@ static void generateEitherEnum(final Writer writer) throws IOException
 
  static void generateReadBuf(final Appendable writer, final ByteOrder byteOrder) throws IOException
  {
- indent(writer, 0, "#[derive(Debug, Default)]\n");
+ indent(writer, 0, "#[derive(Clone, Copy, Debug, Default)]\n");
  indent(writer, 0, "pub struct %s<%s> {\n", READ_BUF_TYPE, BUF_LIFETIME);
  RustUtil.indent(writer, 1, "data: &%s [u8],\n", BUF_LIFETIME);
  indent(writer, 0, "}\n");

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/rust/MessageCoderDef.java

@@ -155,7 +155,15 @@ void appendMessageHeaderDecoderFn(final Appendable out) throws IOException
 
  void appendMessageStruct(final Appendable out, final String structName) throws IOException
  {
- indent(out, 1, "#[derive(Debug, Default)]\n");
+ if (this.codecType == Decoder)
+ {
+ indent(out, 1, "#[derive(Clone, Copy, Debug, Default)]\n");
+ }
+ else
+ {
+ indent(out, 1, "#[derive(Debug, Default)]\n");
+ }
+
  indent(out, 1, "pub struct %s {\n", withLifetime(structName));
  indent(out, 2, "buf: %s,\n", withLifetime(this.codecType.bufType()));
  indent(out, 2, "initial_offset: usize,\n");