Add custom operator to handle data

Author: hayashikun

macaron.xcodeproj/project.pbxproj

@@ -479,7 +479,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = tokyo.yagra.macaronTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
@@ -493,7 +493,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = tokyo.yagra.macaronTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_SWIFT3_OBJC_INFERENCE = On;
+				SWIFT_SWIFT3_OBJC_INFERENCE = Off;
 				SWIFT_VERSION = 4.0;
 			};
 			name = Release;

macaron/MacaronCellData.swift

@@ -12,11 +12,17 @@ public protocol MacaronCellDataType {
     var CellClassName: String { get }
 }
 
-public extension MacaronCellDataType {
-    public func handle(_ handler: (Self) -> Void) -> Self {
-        handler(self)
-        return self
-    }
+
+precedencegroup HandlingCondition {
+    associativity: left
+    higherThan: AssignmentPrecedence
+    lowerThan: TernaryPrecedence
+}
+
+infix operator <!: HandlingCondition
+public func <! <D>(d: D, handler: (D) -> Void) -> D where D: MacaronCellDataType {
+    handler(d)
+    return d
 }
 
 open class MacaronCellData<Cell: MacaronCellType>: MacaronCellDataType {

macaronTests/macaronTests.swift

@@ -13,17 +13,17 @@ class macaronTests: XCTestCase {
 
     override func setUp() {
         super.setUp()
-        // Put setup code here. This method is called before the invocation of each test method in the class.
     }
 
     override func tearDown() {
-        // Put teardown code here. This method is called after the invocation of each test method in the class.
         super.tearDown()
     }
-    
-    func testExample() {
-        // This is an example of a functional test case.
-        // Use XCTAssert and related functions to verify your tests produce the correct results.
+
+    func testCustomOperator() {
+        let data = TextCellData(text: "hoge") <! {
+            $0.text = "fuga"
+        }
+        XCTAssertEqual(data.text, "fuga")
     }
 
     func testPerformanceExample() {