change io cfg to be non-std rather than dkg

Cargo.toml

@@ -24,7 +24,7 @@ hex-literal = "0.4.1"
 rand = "0.8.5"
 
 [features]
-default = ["dkg"]
+default = ["signing"]
 
 std = []
 signing = ["dep:blake3", "dep:rand_chacha", "std"]

src/lib.rs

@@ -42,7 +42,7 @@ mod io {
 #[cfg(not(feature = "std"))]
 extern crate alloc;
 
-#[cfg(feature = "dkg")]
+#[cfg(not(feature = "std"))]
 mod io {
     use core::cmp;
     use core::mem;

src/signing_commitment.rs

@@ -167,7 +167,7 @@ impl SigningCommitment {
 
     pub fn serialize(&self) -> [u8; SIGNING_COMMITMENT_LEN] {
         let mut bytes = [0u8; SIGNING_COMMITMENT_LEN];
-        self.serialize_into(&mut bytes)
+        self.serialize_into(&mut bytes[..])
             .expect("serialization failed");
         bytes
     }