proc macro works

1 files changed, 31 insertions, 0 deletions

diff --git a/ebml/src/lib.rs b/ebml/src/lib.rs
index 116b8e2..acebae3 100644
--- a/ebml/src/lib.rs
+++ b/ebml/src/lib.rs
@@ -47,3 +47,34 @@ impl EbmlReader {
         })
     }
 }
+
+pub trait ValueFromBuf: Sized {
+    fn from_buf(buf: &[u8]) -> anyhow::Result<Self>;
+}
+
+impl ValueFromBuf for u64 {
+    fn from_buf(buf: &[u8]) -> anyhow::Result<Self> {
+        if buf.len() != 8 {
+            bail!("u64 is not 64 bits long")
+        }
+        Ok((buf[0] as u64) << 24
+            | (buf[1] as u64) << 16
+            | (buf[2] as u64) << 8
+            | (buf[3] as u64) << 0)
+    }
+}
+impl ValueFromBuf for Vec<u8> {
+    fn from_buf(buf: &[u8]) -> anyhow::Result<Self> {
+        Ok(buf.to_vec())
+    }
+}
+impl ValueFromBuf for String {
+    fn from_buf(buf: &[u8]) -> anyhow::Result<Self> {
+        Ok(String::from_utf8(Vec::from(buf))?)
+    }
+}
+impl ValueFromBuf for Master {
+    fn from_buf(_buf: &[u8]) -> anyhow::Result<Self> {
+        Ok(Master::Start)
+    }
+}