[String] UTF8View implements withContiguousStorageIfAvailable

milseman · milseman · commit 7f301039a49e · 2018-12-10T15:58:29.000-08:00
diff --git a/stdlib/public/core/StringUTF8View.swift b/stdlib/public/core/StringUTF8View.swift
@@ -510,3 +510,13 @@ extension String.Index {
     return target._guts.isOnUnicodeScalarBoundary(self)
   }
 }
+
+extension String.UTF8View {
+  @inlinable
+  public func withContiguousStorageIfAvailable<R>(
+    _ body: (UnsafeBufferPointer<Element>) throws -> R
+  ) rethrows -> R? {
+    guard _guts.isFastUTF8 else { return nil }
+    return try _guts.withFastUTF8(body)
+  }
+}

Original file line number	Diff line number	Diff line change
`@@ -510,3 +510,13 @@ extension String.Index {`
`510`	`510`	`return target._guts.isOnUnicodeScalarBoundary(self)`
`511`	`511`	`}`
`512`	`512`	`}`
	`513`	`+`
	`514`	`+extension String.UTF8View {`
	`515`	`+ @inlinable`
	`516`	`+ public func withContiguousStorageIfAvailable<R>(`
	`517`	`+ _ body: (UnsafeBufferPointer<Element>) throws -> R`
	`518`	`+ ) rethrows -> R? {`
	`519`	`+ guard _guts.isFastUTF8 else { return nil }`
	`520`	`+ return try _guts.withFastUTF8(body)`
	`521`	`+ }`
	`522`	`+}`