Change method return type

Any SignedAmount can now be cast to Amount since the range is the same.
Specifically, the range for SignedAmount is (- 21 million, 21 million)
while the range for Amount is (0, 21 million).  Therefore any value from
Amount can be cast to a SignedAmount and it will work.  Note it's not
the same and still requires checking when going from SignedAmount to
Amount since Amount can't handle the negative range.

As a side effect of changing the return type, TryFrom is no longer valid
and does not compile.  Therefore in addition to changing the return
type, TryFrom is also removed.

api/units/all-features.txt

@@ -198,7 +198,6 @@ impl core::convert::TryFrom<alloc::string::String> for bitcoin_units::locktime::
 impl core::convert::TryFrom<alloc::string::String> for bitcoin_units::locktime::relative::Height
 impl core::convert::TryFrom<alloc::string::String> for bitcoin_units::locktime::relative::Time
 impl core::convert::TryFrom<alloc::string::String> for bitcoin_units::weight::Weight
-impl core::convert::TryFrom<bitcoin_units::Amount> for bitcoin_units::SignedAmount
 impl core::convert::TryFrom<bitcoin_units::SignedAmount> for bitcoin_units::Amount
 impl core::convert::TryFrom<bitcoin_units::block::BlockHeight> for bitcoin_units::locktime::absolute::Height
 impl core::convert::TryFrom<bitcoin_units::block::BlockInterval> for bitcoin_units::locktime::relative::Height
@@ -831,7 +830,7 @@ pub fn bitcoin_units::Amount::sum<I: core::iter::traits::iterator::Iterator<Item
 pub fn bitcoin_units::Amount::sum<I>(iter: I) -> Self where I: core::iter::traits::iterator::Iterator<Item = &'a bitcoin_units::Amount>
 pub fn bitcoin_units::Amount::to_btc(self) -> f64
 pub fn bitcoin_units::Amount::to_float_in(self, denom: bitcoin_units::amount::Denomination) -> f64
-pub fn bitcoin_units::Amount::to_signed(self) -> core::result::Result<bitcoin_units::SignedAmount, bitcoin_units::amount::OutOfRangeError>
+pub fn bitcoin_units::Amount::to_signed(self) -> bitcoin_units::SignedAmount
 pub fn bitcoin_units::Amount::to_string_in(self, denom: bitcoin_units::amount::Denomination) -> alloc::string::String
 pub fn bitcoin_units::Amount::to_string_with_denomination(self, denom: bitcoin_units::amount::Denomination) -> alloc::string::String
 pub fn bitcoin_units::Amount::try_from(value: bitcoin_units::SignedAmount) -> core::result::Result<Self, Self::Error>
@@ -890,7 +889,6 @@ pub fn bitcoin_units::SignedAmount::to_float_in(self, denom: bitcoin_units::amou
 pub fn bitcoin_units::SignedAmount::to_string_in(self, denom: bitcoin_units::amount::Denomination) -> alloc::string::String
 pub fn bitcoin_units::SignedAmount::to_string_with_denomination(self, denom: bitcoin_units::amount::Denomination) -> alloc::string::String
 pub fn bitcoin_units::SignedAmount::to_unsigned(self) -> core::result::Result<bitcoin_units::Amount, bitcoin_units::amount::OutOfRangeError>
-pub fn bitcoin_units::SignedAmount::try_from(value: bitcoin_units::Amount) -> core::result::Result<Self, Self::Error>
 pub fn bitcoin_units::SignedAmount::type_prefix(_: private::Token) -> &'static str
 pub fn bitcoin_units::SignedAmount::unchecked_add(self, rhs: bitcoin_units::SignedAmount) -> bitcoin_units::SignedAmount
 pub fn bitcoin_units::SignedAmount::unchecked_sub(self, rhs: bitcoin_units::SignedAmount) -> bitcoin_units::SignedAmount
@@ -1255,7 +1253,6 @@ pub type bitcoin_units::Amount::Error = bitcoin_units::amount::OutOfRangeError
 pub type bitcoin_units::Amount::Output = bitcoin_units::Amount
 pub type bitcoin_units::Amount::Output = bitcoin_units::fee_rate::FeeRate
 pub type bitcoin_units::SignedAmount::Err = bitcoin_units::amount::ParseError
-pub type bitcoin_units::SignedAmount::Error = bitcoin_units::amount::OutOfRangeError
 pub type bitcoin_units::SignedAmount::Output = bitcoin_units::SignedAmount
 pub type bitcoin_units::amount::Denomination::Err = bitcoin_units::amount::ParseDenominationError
 pub type bitcoin_units::block::BlockHeight::Err = bitcoin_units::parse::ParseIntError

api/units/alloc-only.txt

@@ -194,7 +194,6 @@ impl core::convert::TryFrom<alloc::string::String> for bitcoin_units::locktime::
 impl core::convert::TryFrom<alloc::string::String> for bitcoin_units::locktime::relative::Height
 impl core::convert::TryFrom<alloc::string::String> for bitcoin_units::locktime::relative::Time
 impl core::convert::TryFrom<alloc::string::String> for bitcoin_units::weight::Weight
-impl core::convert::TryFrom<bitcoin_units::Amount> for bitcoin_units::SignedAmount
 impl core::convert::TryFrom<bitcoin_units::SignedAmount> for bitcoin_units::Amount
 impl core::convert::TryFrom<bitcoin_units::block::BlockHeight> for bitcoin_units::locktime::absolute::Height
 impl core::convert::TryFrom<bitcoin_units::block::BlockInterval> for bitcoin_units::locktime::relative::Height
@@ -772,7 +771,7 @@ pub fn bitcoin_units::Amount::sum<I: core::iter::traits::iterator::Iterator<Item
 pub fn bitcoin_units::Amount::sum<I>(iter: I) -> Self where I: core::iter::traits::iterator::Iterator<Item = &'a bitcoin_units::Amount>
 pub fn bitcoin_units::Amount::to_btc(self) -> f64
 pub fn bitcoin_units::Amount::to_float_in(self, denom: bitcoin_units::amount::Denomination) -> f64
-pub fn bitcoin_units::Amount::to_signed(self) -> core::result::Result<bitcoin_units::SignedAmount, bitcoin_units::amount::OutOfRangeError>
+pub fn bitcoin_units::Amount::to_signed(self) -> bitcoin_units::SignedAmount
 pub fn bitcoin_units::Amount::to_string_in(self, denom: bitcoin_units::amount::Denomination) -> alloc::string::String
 pub fn bitcoin_units::Amount::to_string_with_denomination(self, denom: bitcoin_units::amount::Denomination) -> alloc::string::String
 pub fn bitcoin_units::Amount::try_from(value: bitcoin_units::SignedAmount) -> core::result::Result<Self, Self::Error>
@@ -820,7 +819,6 @@ pub fn bitcoin_units::SignedAmount::to_float_in(self, denom: bitcoin_units::amou
 pub fn bitcoin_units::SignedAmount::to_string_in(self, denom: bitcoin_units::amount::Denomination) -> alloc::string::String
 pub fn bitcoin_units::SignedAmount::to_string_with_denomination(self, denom: bitcoin_units::amount::Denomination) -> alloc::string::String
 pub fn bitcoin_units::SignedAmount::to_unsigned(self) -> core::result::Result<bitcoin_units::Amount, bitcoin_units::amount::OutOfRangeError>
-pub fn bitcoin_units::SignedAmount::try_from(value: bitcoin_units::Amount) -> core::result::Result<Self, Self::Error>
 pub fn bitcoin_units::SignedAmount::unchecked_add(self, rhs: bitcoin_units::SignedAmount) -> bitcoin_units::SignedAmount
 pub fn bitcoin_units::SignedAmount::unchecked_sub(self, rhs: bitcoin_units::SignedAmount) -> bitcoin_units::SignedAmount
 pub fn bitcoin_units::SignedAmount::unsigned_abs(self) -> bitcoin_units::Amount
@@ -1117,7 +1115,6 @@ pub type bitcoin_units::Amount::Error = bitcoin_units::amount::OutOfRangeError
 pub type bitcoin_units::Amount::Output = bitcoin_units::Amount
 pub type bitcoin_units::Amount::Output = bitcoin_units::fee_rate::FeeRate
 pub type bitcoin_units::SignedAmount::Err = bitcoin_units::amount::ParseError
-pub type bitcoin_units::SignedAmount::Error = bitcoin_units::amount::OutOfRangeError
 pub type bitcoin_units::SignedAmount::Output = bitcoin_units::SignedAmount
 pub type bitcoin_units::amount::Denomination::Err = bitcoin_units::amount::ParseDenominationError
 pub type bitcoin_units::block::BlockHeight::Err = bitcoin_units::parse::ParseIntError

api/units/no-features.txt

@@ -178,7 +178,6 @@ impl core::convert::TryFrom<&str> for bitcoin_units::locktime::absolute::Time
 impl core::convert::TryFrom<&str> for bitcoin_units::locktime::relative::Height
 impl core::convert::TryFrom<&str> for bitcoin_units::locktime::relative::Time
 impl core::convert::TryFrom<&str> for bitcoin_units::weight::Weight
-impl core::convert::TryFrom<bitcoin_units::Amount> for bitcoin_units::SignedAmount
 impl core::convert::TryFrom<bitcoin_units::SignedAmount> for bitcoin_units::Amount
 impl core::convert::TryFrom<bitcoin_units::block::BlockHeight> for bitcoin_units::locktime::absolute::Height
 impl core::convert::TryFrom<bitcoin_units::block::BlockInterval> for bitcoin_units::locktime::relative::Height
@@ -750,7 +749,7 @@ pub fn bitcoin_units::Amount::sub_assign(&mut self, rhs: &bitcoin_units::Amount)
 pub fn bitcoin_units::Amount::sub_assign(&mut self, rhs: bitcoin_units::Amount)
 pub fn bitcoin_units::Amount::sum<I: core::iter::traits::iterator::Iterator<Item = Self>>(iter: I) -> Self
 pub fn bitcoin_units::Amount::sum<I>(iter: I) -> Self where I: core::iter::traits::iterator::Iterator<Item = &'a bitcoin_units::Amount>
-pub fn bitcoin_units::Amount::to_signed(self) -> core::result::Result<bitcoin_units::SignedAmount, bitcoin_units::amount::OutOfRangeError>
+pub fn bitcoin_units::Amount::to_signed(self) -> bitcoin_units::SignedAmount
 pub fn bitcoin_units::Amount::try_from(value: bitcoin_units::SignedAmount) -> core::result::Result<Self, Self::Error>
 pub fn bitcoin_units::Amount::unchecked_add(self, rhs: bitcoin_units::Amount) -> bitcoin_units::Amount
 pub fn bitcoin_units::Amount::unchecked_sub(self, rhs: bitcoin_units::Amount) -> bitcoin_units::Amount
@@ -790,7 +789,6 @@ pub fn bitcoin_units::SignedAmount::sub_assign(&mut self, rhs: bitcoin_units::Si
 pub fn bitcoin_units::SignedAmount::sum<I: core::iter::traits::iterator::Iterator<Item = Self>>(iter: I) -> Self
 pub fn bitcoin_units::SignedAmount::sum<I>(iter: I) -> Self where I: core::iter::traits::iterator::Iterator<Item = &'a bitcoin_units::SignedAmount>
 pub fn bitcoin_units::SignedAmount::to_unsigned(self) -> core::result::Result<bitcoin_units::Amount, bitcoin_units::amount::OutOfRangeError>
-pub fn bitcoin_units::SignedAmount::try_from(value: bitcoin_units::Amount) -> core::result::Result<Self, Self::Error>
 pub fn bitcoin_units::SignedAmount::unchecked_add(self, rhs: bitcoin_units::SignedAmount) -> bitcoin_units::SignedAmount
 pub fn bitcoin_units::SignedAmount::unchecked_sub(self, rhs: bitcoin_units::SignedAmount) -> bitcoin_units::SignedAmount
 pub fn bitcoin_units::SignedAmount::unsigned_abs(self) -> bitcoin_units::Amount
@@ -1071,7 +1069,6 @@ pub type bitcoin_units::Amount::Error = bitcoin_units::amount::OutOfRangeError
 pub type bitcoin_units::Amount::Output = bitcoin_units::Amount
 pub type bitcoin_units::Amount::Output = bitcoin_units::fee_rate::FeeRate
 pub type bitcoin_units::SignedAmount::Err = bitcoin_units::amount::ParseError
-pub type bitcoin_units::SignedAmount::Error = bitcoin_units::amount::OutOfRangeError
 pub type bitcoin_units::SignedAmount::Output = bitcoin_units::SignedAmount
 pub type bitcoin_units::amount::Denomination::Err = bitcoin_units::amount::ParseDenominationError
 pub type bitcoin_units::block::BlockHeight::Err = bitcoin_units::parse::ParseIntError

bitcoin/src/blockdata/transaction.rs

@@ -790,8 +790,8 @@ pub fn effective_value(
     value: Amount,
 ) -> Option<SignedAmount> {
     let weight = satisfaction_weight.checked_add(TX_IN_BASE_WEIGHT)?;
-    let signed_input_fee = fee_rate.checked_mul_by_weight(weight)?.to_signed().ok()?;
+    let signed_input_fee = fee_rate.checked_mul_by_weight(weight)?.to_signed();
-    value.to_signed().ok()?.checked_sub(signed_input_fee)
+    value.to_signed().checked_sub(signed_input_fee)
 }
 
 /// Predicts the weight of a to-be-constructed transaction.
@@ -1673,7 +1673,7 @@ mod tests {
 
         // 10 sat/kwu * (204wu + BASE_WEIGHT) = 4 sats
         let expected_fee = "4 sats".parse::<SignedAmount>().unwrap();
-        let expected_effective_value = value.to_signed().unwrap() - expected_fee;
+        let expected_effective_value = value.to_signed() - expected_fee;
         assert_eq!(effective_value, expected_effective_value);
     }
 

units/src/amount/signed.rs

@@ -566,12 +566,6 @@ impl FromStr for SignedAmount {
     }
 }
 
-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();

units/src/amount/tests.rs

@@ -71,13 +71,6 @@ fn from_int_btc() {
     assert_eq!(Amount::from_sat(200_000_000), amt);
 }
 
-#[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::from_sat(123));
-}
-
 #[test]
 fn test_amount_try_from_signed_amount() {
     let sa_positive = SignedAmount::from_sat(123);
@@ -473,12 +466,11 @@ fn test_unsigned_signed_conversion() {
     let ua = Amount::from_sat;
     let max_sats: u64 = Amount::MAX.to_sat();
 
-    assert_eq!(ua(max_sats).to_signed(), Ok(sa(max_sats as i64)));
+    assert_eq!(ua(max_sats).to_signed(), sa(max_sats as i64));
-    assert_eq!(ua(i64::MAX as u64 + 1).to_signed(), Err(OutOfRangeError::too_big(true)));
 
     assert_eq!(sa(max_sats as i64).to_unsigned(), Ok(ua(max_sats)));
 
-    assert_eq!(sa(max_sats as i64).to_unsigned().unwrap().to_signed(), Ok(sa(max_sats as i64)));
+    assert_eq!(sa(max_sats as i64).to_unsigned().unwrap().to_signed(), sa(max_sats as i64));
 }
 
 #[test]

units/src/amount/unsigned.rs

@@ -438,17 +438,9 @@ impl Amount {
     pub fn unchecked_sub(self, rhs: Amount) -> Amount { Self(self.0 - rhs.0) }
 
     /// Converts to a signed amount.
-    ///
-    /// # Errors
-    ///
-    /// If the amount is too big.
     #[rustfmt::skip] // Moves code comments to the wrong line.
-    pub fn to_signed(self) -> Result<SignedAmount, OutOfRangeError> {
+    pub fn to_signed(self) -> SignedAmount {
-        if self.to_sat() > SignedAmount::MAX.to_sat() as u64 { // Cast ok, signed max is positive and fits in u64.
+        SignedAmount::from_sat_unchecked(self.to_sat() as i64) // Cast ok, signed amount and amount share positive range.
-            Err(OutOfRangeError::too_big(true))
-        } else {
-            Ok(SignedAmount::from_sat(self.to_sat() as i64)) // Cast ok, checked not too big above.
-        }
     }
 
     /// Checks if the amount is below the maximum value. Returns `None` if it is above.