Add Zip2Sequence.underestimatedCount (#21530)

dennisvennink · stephentyrone · commit 45429ffa2419 · 2019-01-02T12:46:49.000-05:00
diff --git a/stdlib/public/core/Zip.swift b/stdlib/public/core/Zip.swift
@@ -144,4 +144,12 @@ extension Zip2Sequence: Sequence {
       _sequence1.makeIterator(),
       _sequence2.makeIterator())
   }
+
+  @inlinable // generic-performance
+  public var underestimatedCount: Int {
+    return Swift.min(
+      _sequence1.underestimatedCount,
+      _sequence2.underestimatedCount
+    )
+  }
 }

Original file line number	Diff line number	Diff line change
`@@ -144,4 +144,12 @@ extension Zip2Sequence: Sequence {`
`144`	`144`	`_sequence1.makeIterator(),`
`145`	`145`	`_sequence2.makeIterator())`
`146`	`146`	`}`
	`147`	`+`
	`148`	`+ @inlinable // generic-performance`
	`149`	`+ public var underestimatedCount: Int {`
	`150`	`+ return Swift.min(`
	`151`	`+ _sequence1.underestimatedCount,`
	`152`	`+ _sequence2.underestimatedCount`
	`153`	`+ )`
	`154`	`+ }`
`147`	`155`	`}`