<label> body => _ body

stdlib/private/StdlibUnittest/RaceTest.swift

@@ -596,7 +596,9 @@ internal struct ClosureBasedRaceTest : RaceTestWithPerTrialData {
   ) {}
 }
 
-public func runRaceTest(trials: Int, threads: Int? = nil, body: () -> ()) {
+public func runRaceTest(
+  trials: Int, threads: Int? = nil, invoking body: () -> ()
+) {
   ClosureBasedRaceTest.thread = body
   runRaceTest(ClosureBasedRaceTest.self, trials: trials, threads: threads)
 }

stdlib/private/StdlibUnittest/StdlibCoreExtras.swift

@@ -214,7 +214,7 @@ extension MutableCollection
 }
 
 /// Generate all permutations.
-public func forAllPermutations(_ size: Int, body: ([Int]) -> Void) {
+public func forAllPermutations(_ size: Int, _ body: ([Int]) -> Void) {
   var data = Array(0..<size)
   repeat {
     body(data)
@@ -223,7 +223,7 @@ public func forAllPermutations(_ size: Int, body: ([Int]) -> Void) {
 
 /// Generate all permutations.
 public func forAllPermutations<S : Sequence>(
-  _ sequence: S, body: ([S.Iterator.Element]) -> Void
+  _ sequence: S, _ body: ([S.Iterator.Element]) -> Void
 ) {
   let data = Array(sequence)
   forAllPermutations(data.count) {

stdlib/private/StdlibUnittest/StdlibUnittest.swift.gyb

@@ -107,7 +107,7 @@ var _seenExpectCrash = false
 /// Run `body` and expect a failure to happen.
 ///
 /// The check passes iff `body` triggers one or more failures.
-public func expectFailure(${TRACE}, body: () -> Void) {
+public func expectFailure(${TRACE}, invoking body: () -> Void) {
   let startAnyExpectFailed = _anyExpectFailed
   _anyExpectFailed = false
   body()

stdlib/private/StdlibUnittest/TypeIndexed.swift

@@ -59,7 +59,7 @@ extension TypeIndexed where Value : Strideable {
     showFrame: Bool = true,
     stackTrace: SourceLocStack = SourceLocStack(),  
     file: String = #file, line: UInt = #line,
-    body: () -> R
+    invoking body: () -> R
   ) -> R {
     let expected = self[t].advanced(by: 1)
     let r = body()
@@ -77,7 +77,7 @@ extension TypeIndexed where Value : Equatable {
     showFrame: Bool = true,
     stackTrace: SourceLocStack = SourceLocStack(),  
     file: String = #file, line: UInt = #line,
-    body: () -> R
+    invoking body: () -> R
   ) -> R {
     let expected = self[t]
     let r = body()

stdlib/private/StdlibUnittestFoundationExtras/StdlibUnittestFoundationExtras.swift

@@ -65,7 +65,7 @@ public func withOverriddenLocaleCurrentLocale<Result>(
 /// return-autoreleased optimization.)
 @inline(never)
 public func autoreleasepoolIfUnoptimizedReturnAutoreleased(
-  _ body: @noescape () -> Void
+  invoking body: @noescape () -> Void
 ) {
 #if arch(i386) && (os(iOS) || os(watchOS))
   autoreleasepool(body)

stdlib/public/SDK/Foundation/NSStringAPI.swift

@@ -76,7 +76,8 @@ extension Optional {
   /// `body` is complicated than that results in unnecessarily repeated code.
   internal func _withNilOrAddress<NSType : AnyObject, ResultType>(
     of object: inout NSType?,
-    body: @noescape (AutoreleasingUnsafeMutablePointer<NSType?>?) -> ResultType
+    _ body:
+      @noescape (AutoreleasingUnsafeMutablePointer<NSType?>?) -> ResultType
   ) -> ResultType {
     return self == nil ? body(nil) : body(&object)
   }
@@ -495,7 +496,9 @@ extension String {
   //     enumerateLinesUsing:(void (^)(NSString *line, BOOL *stop))block
 
   /// Enumerates all the lines in a string.
-  public func enumerateLines(_ body: (line: String, stop: inout Bool) -> ()) {
+  public func enumerateLines(
+    invoking body: (line: String, stop: inout Bool) -> ()
+  ) {
     _ns.enumerateLines {
       (line: String, stop: UnsafeMutablePointer<ObjCBool>)
     in
@@ -526,7 +529,7 @@ extension String {
     scheme tagScheme: String,
     options opts: NSLinguisticTagger.Options = [],
     orthography: NSOrthography? = nil,
-    _ body:
+    invoking body:
       (String, Range<Index>, Range<Index>, inout Bool) -> ()
   ) {
     _ns.enumerateLinguisticTags(

stdlib/public/SDK/ObjectiveC/ObjectiveC.swift

@@ -187,7 +187,7 @@ func __pushAutoreleasePool() -> OpaquePointer
 func __popAutoreleasePool(_ pool: OpaquePointer)
 
 public func autoreleasepool<Result>(
-  _ body: @noescape () throws -> Result
+  invoking body: @noescape () throws -> Result
 ) rethrows -> Result {
   let pool = __pushAutoreleasePool()
   defer {

stdlib/public/core/LifetimeManager.swift

@@ -13,19 +13,19 @@
 /// Evaluate `f()` and return its result, ensuring that `x` is not
 /// destroyed before f returns.
 public func withExtendedLifetime<T, Result>(
-  _ x: T, _ f: @noescape () throws -> Result
+  _ x: T, _ body: @noescape () throws -> Result
 ) rethrows -> Result {
   defer { _fixLifetime(x) }
-  return try f()
+  return try body()
 }
 
 /// Evaluate `f(x)` and return its result, ensuring that `x` is not
 /// destroyed before f returns.
 public func withExtendedLifetime<T, Result>(
-  _ x: T, _ f: @noescape (T) throws -> Result
+  _ x: T, _ body: @noescape (T) throws -> Result
 ) rethrows -> Result {
   defer { _fixLifetime(x) }
-  return try f(x)
+  return try body(x)
 }
 
 extension String {
@@ -41,10 +41,10 @@ extension String {
   ///   it is used as the return value of the `withCString(_:)` method.
   /// - Returns: The return value of the `f` closure, if any.
   public func withCString<Result>(
-    _ f: @noescape (UnsafePointer<Int8>) throws -> Result
+    _ body: @noescape (UnsafePointer<Int8>) throws -> Result
   ) rethrows -> Result {
     return try self.nulTerminatedUTF8.withUnsafeBufferPointer {
-      try f(UnsafePointer($0.baseAddress!))
+      try body(UnsafePointer($0.baseAddress!))
     }
   }
 }

stdlib/public/core/StaticString.swift

@@ -124,7 +124,7 @@ public struct StaticString
   ///   `withUTF8Buffer(invoke:)` method.
   /// - Returns: The return value of the `body` closure, if any.
   public func withUTF8Buffer<R>(
-    invoke body: @noescape (UnsafeBufferPointer<UInt8>) -> R) -> R {
+    _ body: @noescape (UnsafeBufferPointer<UInt8>) -> R) -> R {
     if hasPointerRepresentation {
       return body(UnsafeBufferPointer(
         start: utf8Start, count: Int(utf8CodeUnitCount)))

stdlib/public/core/StringCharacterView.swift

@@ -103,7 +103,9 @@ extension String {
   /// - Parameter body: A closure that takes a character view as its argument.
   /// - Returns: The return value of the `body` closure, if any, is the return
   ///   value of this method.
-  public mutating func withMutableCharacters<R>(_ body: (inout CharacterView) -> R) -> R {
+  public mutating func withMutableCharacters<R>(
+    _ body: (inout CharacterView) -> R
+  ) -> R {
     // Naively mutating self.characters forces multiple references to
     // exist at the point of mutation. Instead, temporarily move the
     // core of this string into a CharacterView.

stdlib/public/core/Unmanaged.swift

@@ -183,10 +183,10 @@ public struct Unmanaged<Instance : AnyObject> {
   ///    }
   ///  }
   public func _withUnsafeGuaranteedRef<Result>(
-    _ closure: @noescape (Instance) throws -> Result
+    _ body: @noescape (Instance) throws -> Result
   ) rethrows -> Result {
     let (guaranteedInstance, token) = Builtin.unsafeGuaranteed(_value)
-    let result = try closure(guaranteedInstance)
+    let result = try body(guaranteedInstance)
     Builtin.unsafeGuaranteedEnd(token)
     return result
   }

stdlib/public/core/VarArgs.swift

@@ -65,18 +65,18 @@ let _x86_64RegisterSaveWords = _x86_64CountGPRegisters + _x86_64CountSSERegister
 
 /// Invoke `body` with a C `va_list` argument derived from `args`.
 public func withVaList<R>(_ args: [CVarArg],
-  invoke body: @noescape (CVaListPointer) -> R) -> R {
+  _ body: @noescape (CVaListPointer) -> R) -> R {
   let builder = _VaListBuilder()
   for a in args {
     builder.append(a)
   }
-  return _withVaList(builder, invoke: body)
+  return _withVaList(builder, body)
 }
 
 /// Invoke `body` with a C `va_list` argument derived from `builder`.
 internal func _withVaList<R>(
   _ builder: _VaListBuilder,
-  invoke body: @noescape (CVaListPointer) -> R
+  _ body: @noescape (CVaListPointer) -> R
 ) -> R {
   let result = body(builder.va_list())
   _fixLifetime(builder)

test/1_stdlib/ArrayTraps.swift.gyb

@@ -138,7 +138,7 @@ ArrayTraps.test("unsafeLength")
 
   expectCrashLater()
 
-  a.withUnsafeBufferPointer {
+  _ = a.withUnsafeBufferPointer {
     UnsafeBufferPointer(start: $0.baseAddress, count: -1)
   }
 }

test/IDE/complete_literal.swift

@@ -38,7 +38,7 @@
 }
 
 // LITERAL4:         Begin completions
-// LITERAL4-DAG:     Decl[InstanceMethod]/CurrNominal:   withCString({#(f): (UnsafePointer<Int8>) throws -> Result##(UnsafePointer<Int8>) throws -> Result#})[' rethrows'][#Result#]; name=withCString(f: (UnsafePointer<Int8>) throws -> Result) rethrows{{$}}
+// LITERAL4-DAG:     Decl[InstanceMethod]/CurrNominal:   withCString({#(body): (UnsafePointer<Int8>) throws -> Result##(UnsafePointer<Int8>) throws -> Result#})[' rethrows'][#Result#]; name=withCString(body: (UnsafePointer<Int8>) throws -> Result) rethrows{{$}}
 
 // FIXME: we should show the qualified String.Index type.
 // rdar://problem/20788802

test/Prototypes/Result.swift

@@ -79,7 +79,9 @@ public func ?? <T> (
 }
 
 /// Translate the execution of a throwing closure into a Result
-func catchResult<Success>(body: () throws -> Success) -> Result<Success> {
+func catchResult<Success>(
+  invoking body: () throws -> Success
+) -> Result<Success> {
   do {
     return try .Success(body())
   }