Merge rust-bitcoin/rust-bitcoin#2462: feat: implement TryFrom trait to `SignedAmount` and `Amount`

251579f4ef feat: implement TryFrom trait to SignedAmount and Amount (Sumit Kumar)

Pull request description:

  Closes: #2245

  Adds `TryFrom<SignedAmount> for Amount` and `TryFrom<Amount> for Amount` in units module

ACKs for top commit:
  tcharding:
    ACK 251579f4ef
  Kixunil:
    ACK 251579f4ef
  apoelstra:
    ACK 251579f4ef

Tree-SHA512: 3e58d7a891019ccd272417eadc977037167439e3385a7b47c060fe93eba9c47fc37cdc0ca5551174ef2d93b256b2804ad7c01f5f2470ef9e9b7b912877aed11c

units/src/amount.rs

@@ -865,9 +865,9 @@ impl Amount {
     pub fn checked_rem(self, rhs: u64) -> Option<Amount> { self.0.checked_rem(rhs).map(Amount) }
 
     /// Convert to a signed amount.
-    pub fn to_signed(self) -> Result<SignedAmount, ParseAmountError> {
+    pub fn to_signed(self) -> Result<SignedAmount, OutOfRangeError> {
         if self.to_sat() > SignedAmount::MAX.to_sat() as u64 {
-            Err(ParseAmountError::OutOfRange(OutOfRangeError::too_big(true)))
+            Err(OutOfRangeError::too_big(true))
         } else {
             Ok(SignedAmount::from_sat(self.to_sat() as i64))
         }
@@ -957,6 +957,14 @@ impl FromStr for Amount {
     fn from_str(s: &str) -> Result<Self, Self::Err> { Amount::from_str_with_denomination(s) }
 }
 
+impl TryFrom<SignedAmount> for Amount {
+    type Error = OutOfRangeError;
+
+    fn try_from(value: SignedAmount) -> Result<Self, Self::Error> {
+        value.to_unsigned()
+    }
+}
+
 impl core::iter::Sum for Amount {
     fn sum<I: Iterator<Item = Self>>(iter: I) -> Self {
         let sats: u64 = iter.map(|amt| amt.0).sum();
@@ -1340,6 +1348,14 @@ impl FromStr for SignedAmount {
     fn from_str(s: &str) -> Result<Self, Self::Err> { SignedAmount::from_str_with_denomination(s) }
 }
 
+impl TryFrom<Amount> for SignedAmount {
+    type Error = OutOfRangeError;
+
+    fn try_from(value: Amount) -> Result<Self, Self::Error> {
+        value.to_signed()
+    }
+}
+
 impl core::iter::Sum for SignedAmount {
     fn sum<I: Iterator<Item = Self>>(iter: I) -> Self {
         let sats: i64 = iter.map(|amt| amt.0).sum();
@@ -1710,7 +1726,7 @@ mod verification {
             if n1 <= i64::MAX as u64 {
                 Ok(SignedAmount::from_sat(n1.try_into().unwrap()))
             } else {
-                Err(ParseAmountError::OutOfRange(OutOfRangeError::too_big(true)))
+                Err(OutOfRangeError::too_big(true))
             },
         );
     }
@@ -1841,6 +1857,40 @@ mod tests {
     #[test]
     fn from_int_btc_panic() { Amount::from_int_btc(u64::MAX); }
 
+    #[test]
+    fn test_signed_amount_try_from_amount() {
+        let ua_positive = Amount::from_sat(123);
+        let sa_positive = SignedAmount::try_from(ua_positive).unwrap();
+        assert_eq!(sa_positive, SignedAmount(123));
+
+        let ua_max = Amount::MAX;
+        let result = SignedAmount::try_from(ua_max);
+        assert_eq!(
+            result,
+            Err(OutOfRangeError {
+                is_signed: true,
+                is_greater_than_max: true
+            })
+        );
+    }
+
+    #[test]
+    fn test_amount_try_from_signed_amount() {
+        let sa_positive = SignedAmount(123);
+        let ua_positive = Amount::try_from(sa_positive).unwrap();
+        assert_eq!(ua_positive, Amount::from_sat(123));
+
+        let sa_negative = SignedAmount(-123);
+        let result = Amount::try_from(sa_negative);
+        assert_eq!(
+            result,
+            Err(OutOfRangeError {
+                is_signed: false,
+                is_greater_than_max: false
+            })
+        );
+    }
+
     #[test]
     fn mul_div() {
         let sat = Amount::from_sat;