Remove EmptyFlags construction checks

arkworks-rs#394

Author: lakshya-sky

ff/src/fields/macros.rs

@@ -13,9 +13,8 @@ macro_rules! impl_prime_field_serializer {
                 }
 
                 // Calculate the number of bytes required to represent a field element
-                // serialized with `flags`. If `F::BIT_SIZE < 8`,
-                // this is at most `$byte_size + 1`
-                let output_byte_size = buffer_byte_size(P::MODULUS_BITS as usize + F::BIT_SIZE);
+                // serialized with `flags`.
+                let output_byte_size = Self::zero().serialized_size_with_flags::<F>();
 
                 // Write out `self` to a temporary buffer.
                 // The size of the buffer is $byte_size + 1 because `F::BIT_SIZE`

serialize/src/flags.rs

@@ -51,12 +51,8 @@ impl Flags for EmptyFlags {
     }
 
     #[inline]
-    fn from_u8(value: u8) -> Option<Self> {
-        if (value >> 7) == 0 {
-            Some(EmptyFlags)
-        } else {
-            None
-        }
+    fn from_u8(_: u8) -> Option<Self> {
+        Some(EmptyFlags)
     }
 }