Add `Builder::with_capacity()`

bitcoin/src/blockdata/script/builder.rs

@@ -21,6 +21,10 @@ impl Builder {
     #[inline]
     pub const fn new() -> Self { Builder(ScriptBuf::new(), None) }
 
+    /// Constructs a new empty script builder with at least the specified capacity.
+    #[inline]
+    pub fn with_capacity(capacity: usize) -> Self { Builder(ScriptBuf::with_capacity(capacity), None) }
+
     /// Returns the length in bytes of the script.
     pub fn len(&self) -> usize { self.0.len() }
 

bitcoin/src/blockdata/script/tests.rs

@@ -209,6 +209,13 @@ fn script_builder() {
     );
 }
 
+#[test]
+fn script_builder_with_capacity() {
+    let script = Builder::with_capacity(42);
+
+    assert!(script.into_script().capacity() >= 42);
+}
+
 #[test]
 fn script_generators() {
     let pubkey = "0234e6a79c5359c613762d537e0e19d86c77c1666d8c9ab050f23acd198e97f93e"