tree a705c54449ba60a7afffcd3cd57d2cd624942cd9
parent 4aacf268936d0b7437b992bdc14e4c0fb3e11a87
author Patrick Williams <patrick@stwcx.xyz> 1661787207 -0500
committer Patrick Williams <patrick@stwcx.xyz> 1662052777 +0000

message: add unpack method

Add an unpack method that allows reading from the message as
r-values.  This simplifies the pattern:

```
    foo f{};
    bar b{};
    msg.read(f,b);

    // Can now be written as...

    auto [f, b] = msg.unpack<foo, bar>();
```

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ic2ae7f2c52d41702b8c7c3af6a2efb21558a7579