Use uniform docs for overflow

Trivial change but make all the docs (rustdocs and code comments) use
the same phrase when describing overflow.

units/src/block.rs

@@ -87,13 +87,13 @@ impl BlockHeight {
     /// Returns block height as a `u32`.
     pub const fn to_u32(self) -> u32 { self.0 }
 
-    /// Attempt to subtract two [`BlockHeight`]s, returning `None` in case of overflow.
+    /// Attempt to subtract two [`BlockHeight`]s, returning `None` if overflow occurred.
     #[must_use]
     pub fn checked_sub(self, other: Self) -> Option<BlockHeightInterval> {
         self.0.checked_sub(other.0).map(BlockHeightInterval)
     }
 
-    /// Attempt to add an interval to this [`BlockHeight`], returning `None` in case of overflow.
+    /// Attempt to add an interval to this [`BlockHeight`], returning `None` if overflow occurred.
     #[must_use]
     pub fn checked_add(self, other: BlockHeightInterval) -> Option<Self> {
         self.0.checked_add(other.0).map(Self)
@@ -148,11 +148,11 @@ impl BlockHeightInterval {
     /// Returns block interval as a `u32`.
     pub const fn to_u32(self) -> u32 { self.0 }
 
-    /// Attempt to subtract two [`BlockHeightInterval`]s, returning `None` in case of overflow.
+    /// Attempt to subtract two [`BlockHeightInterval`]s, returning `None` if overflow occurred.
     #[must_use]
     pub fn checked_sub(self, other: Self) -> Option<Self> { self.0.checked_sub(other.0).map(Self) }
 
-    /// Attempt to add two [`BlockHeightInterval`]s, returning `None` in case of overflow.
+    /// Attempt to add two [`BlockHeightInterval`]s, returning `None` if overflow occurred.
     #[must_use]
     pub fn checked_add(self, other: Self) -> Option<Self> { self.0.checked_add(other.0).map(Self) }
 }
@@ -220,13 +220,13 @@ impl BlockMtp {
         Self::from_u32(u32::from(timestamps[5]))
     }
 
-    /// Attempt to subtract two [`BlockMtp`]s, returning `None` in case of overflow.
+    /// Attempt to subtract two [`BlockMtp`]s, returning `None` if overflow occurred.
     #[must_use]
     pub fn checked_sub(self, other: Self) -> Option<BlockMtpInterval> {
         self.0.checked_sub(other.0).map(BlockMtpInterval)
     }
 
-    /// Attempt to add an interval to this [`BlockMtp`], returning `None` in case of overflow.
+    /// Attempt to add an interval to this [`BlockMtp`], returning `None` if overflow occurred.
     #[must_use]
     pub fn checked_add(self, other: BlockMtpInterval) -> Option<Self> {
         self.0.checked_add(other.0).map(Self)
@@ -313,11 +313,11 @@ impl BlockMtpInterval {
         relative::NumberOf512Seconds::from_seconds_ceil(self.to_u32())
     }
 
-    /// Attempt to subtract two [`BlockMtpInterval`]s, returning `None` in case of overflow.
+    /// Attempt to subtract two [`BlockMtpInterval`]s, returning `None` if overflow occurred.
     #[must_use]
     pub fn checked_sub(self, other: Self) -> Option<Self> { self.0.checked_sub(other.0).map(Self) }
 
-    /// Attempt to add two [`BlockMtpInterval`]s, returning `None` in case of overflow.
+    /// Attempt to add two [`BlockMtpInterval`]s, returning `None` if overflow occurred.
     #[must_use]
     pub fn checked_add(self, other: Self) -> Option<Self> { self.0.checked_add(other.0).map(Self) }
 }

units/src/fee_rate/mod.rs

@@ -52,7 +52,8 @@ impl FeeRate {
     /// The fee rate used to compute dust amount.
     pub const DUST: FeeRate = FeeRate::from_sat_per_vb_u32(3);
 
-    /// Constructs a new [`FeeRate`] from satoshis per 1000 weight units.
+    /// Constructs a new [`FeeRate`] from satoshis per 1000 weight units,
+    /// returning `None` if overflow occurred.
     pub const fn from_sat_per_kwu(sat_kwu: u64) -> Option<Self> {
         // No `map()` in const context.
         match sat_kwu.checked_mul(4_000) {
@@ -61,11 +62,8 @@ impl FeeRate {
         }
     }
 
-    /// Constructs a new [`FeeRate`] from satoshis per virtual bytes.
-    ///
-    /// # Errors
-    ///
-    /// Returns [`None`] on arithmetic overflow.
+    /// Constructs a new [`FeeRate`] from satoshis per virtual bytes,
+    /// returning `None` if overflow occurred.
     pub const fn from_sat_per_vb(sat_vb: u64) -> Option<Self> {
         // No `map()` in const context.
         match sat_vb.checked_mul(1_000_000) {
@@ -80,7 +78,8 @@ impl FeeRate {
         FeeRate::from_sat_per_mvb(sat_vb * 1_000_000)
     }
 
-    /// Constructs a new [`FeeRate`] from satoshis per kilo virtual bytes (1,000 vbytes).
+    /// Constructs a new [`FeeRate`] from satoshis per kilo virtual bytes (1,000 vbytes),
+    /// returning `None` if overflow occurred.
     pub const fn from_sat_per_kvb(sat_kvb: u64) -> Option<Self> {
         // No `map()` in const context.
         match sat_kvb.checked_mul(1_000) {
@@ -109,7 +108,7 @@ impl FeeRate {
 
     /// Checked multiplication.
     ///
-    /// Computes `self * rhs` returning [`None`] if overflow occurred.
+    /// Computes `self * rhs`, returning [`None`] if overflow occurred.
     #[must_use]
     pub const fn checked_mul(self, rhs: u64) -> Option<Self> {
         // No `map()` in const context.
@@ -133,7 +132,7 @@ impl FeeRate {
 
     /// Checked addition.
     ///
-    /// Computes `self + rhs` returning [`None`] if overflow occurred.
+    /// Computes `self + rhs` returning [`None`] is case of overflow.
     #[must_use]
     pub const fn checked_add(self, rhs: FeeRate) -> Option<Self> {
         // No `map()` in const context.
@@ -145,7 +144,7 @@ impl FeeRate {
 
     /// Checked subtraction.
     ///
-    /// Computes `self - rhs` returning [`None`] if overflow occurred.
+    /// Computes `self - rhs`, returning [`None`] if overflow occurred.
     #[must_use]
     pub const fn checked_sub(self, rhs: FeeRate) -> Option<Self> {
         // No `map()` in const context.

units/src/locktime/absolute.rs

@@ -114,7 +114,7 @@ impl fmt::Display for ParseHeightError {
 
 #[cfg(feature = "std")]
 impl std::error::Error for ParseHeightError {
-    // To be consistent with `write_err` we need to **not** return source in case of overflow
+    // To be consistent with `write_err` we need to **not** return source if overflow occurred
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { self.0.source() }
 }
 
@@ -239,7 +239,7 @@ impl fmt::Display for ParseTimeError {
 
 #[cfg(feature = "std")]
 impl std::error::Error for ParseTimeError {
-    // To be consistent with `write_err` we need to **not** return source in case of overflow
+    // To be consistent with `write_err` we need to **not** return source if overflow occurred
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> { self.0.source() }
 }
 
@@ -398,7 +398,7 @@ impl ParseError {
         }
     }
 
-    // To be consistent with `write_err` we need to **not** return source in case of overflow
+    // To be consistent with `write_err` we need to **not** return source if overflow occurred
     #[cfg(feature = "std")]
     fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
         use core::num::IntErrorKind;