Merge rust-bitcoin/rust-bitcoin#784: replace unncessary closure with function pointer in FromStr::from_str for Deonomation

8fef869 repalce unncessary extra closure with function pointer in starts_with_uppercase closure inside Denomination from_str (KaFai Choi)

Pull request description:

  Follow-up PR from rust-bitcoin/rust-bitcoin#768

  rust-bitcoin/rust-bitcoin#768 (comment)

ACKs for top commit:
  apoelstra:
    ACK 8fef869
  dr-orlovsky:
    ACK 8fef869

Tree-SHA512: 3fd7d77805e047a692c53ca7677d7857baa00f529e15696790544a47cebe8a143c1c11f95401436d5322b6da24bc61cc9982a069c883b4815b6c50e8bd31553e

Author: dr-orlovsky

src/util/amount.rs

@@ -85,7 +85,7 @@ impl FromStr for Denomination {
         use self::ParseAmountError::*;
         use self::Denomination as D;
 
-        let starts_with_uppercase = || s.starts_with(|ch: char| ch.is_uppercase());
+        let starts_with_uppercase = || s.starts_with(char::is_uppercase);
         match denomination_from_str(s) {
             None => Err(UnknownDenomination(s.to_owned())),
             Some(D::MilliBitcoin) | Some(D::PicoBitcoin) | Some(D::MilliSatoshi) if starts_with_uppercase() => {