Remove unused absolute::Error

The `absolute::Error` is not used, we originally intended it as possibly
useful for users of the library. We have not made effort in other
modules to provide such errors - lets remove it.

bitcoin/src/blockdata/locktime/absolute.rs

@@ -614,60 +614,6 @@ fn is_block_height(n: u32) -> bool { n < LOCK_TIME_THRESHOLD }
 /// Returns true if `n` is a UNIX timestamp i.e., greater than or equal to 500,000,000.
 fn is_block_time(n: u32) -> bool { n >= LOCK_TIME_THRESHOLD }
 
-/// Catchall type for errors that relate to time locks.
-#[derive(Debug, Clone, PartialEq, Eq)]
-#[non_exhaustive]
-pub enum Error {
-    /// An error occurred while converting a `u32` to a lock time variant.
-    Conversion(ConversionError),
-    /// An error occurred while operating on lock times.
-    Operation(OperationError),
-    /// An error occurred while parsing a string into an `u32`.
-    Parse(ParseIntError),
-}
-
-internals::impl_from_infallible!(Error);
-
-impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        use Error::*;
-
-        match *self {
-            Conversion(ref e) => write_err!(f, "error converting lock time value"; e),
-            Operation(ref e) => write_err!(f, "error during lock time operation"; e),
-            Parse(ref e) => write_err!(f, "failed to parse lock time from string"; e),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for Error {
-    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
-        use Error::*;
-
-        match *self {
-            Conversion(ref e) => Some(e),
-            Operation(ref e) => Some(e),
-            Parse(ref e) => Some(e),
-        }
-    }
-}
-
-impl From<ConversionError> for Error {
-    #[inline]
-    fn from(e: ConversionError) -> Self { Self::Conversion(e) }
-}
-
-impl From<OperationError> for Error {
-    #[inline]
-    fn from(e: OperationError) -> Self { Self::Operation(e) }
-}
-
-impl From<ParseIntError> for Error {
-    #[inline]
-    fn from(e: ParseIntError) -> Self { Self::Parse(e) }
-}
-
 /// An error that occurs when converting a `u32` to a lock time variant.
 #[derive(Debug, Clone, PartialEq, Eq)]
 #[non_exhaustive]
@@ -717,38 +663,6 @@ impl fmt::Display for LockTimeUnit {
     }
 }
 
-/// Errors than occur when operating on lock times.
-#[derive(Debug, Clone, PartialEq, Eq)]
-#[non_exhaustive]
-pub enum OperationError {
-    /// Cannot compare different lock time units (height vs time).
-    InvalidComparison,
-}
-
-internals::impl_from_infallible!(OperationError);
-
-impl fmt::Display for OperationError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        use OperationError::*;
-
-        match *self {
-            InvalidComparison =>
-                f.write_str("cannot compare different lock units (height vs time)"),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for OperationError {
-    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
-        use OperationError::*;
-
-        match *self {
-            InvalidComparison => None,
-        }
-    }
-}
-
 /// Internal - common representation for height and time.
 #[derive(Debug, Clone, Eq, PartialEq)]
 enum ParseError {