Implicit constructors for SkFunction are much more readable.

tests/FunctionTest.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkFunction.h"
 #include "Test.h"
 
 static void test_add_five(skiatest::Reporter* r, SkFunction<int(int)>&& f) {
     REPORTER_ASSERT(r, f(3) == 8);
     REPORTER_ASSERT(r, f(4) == 9);
 }
 
 static int add_five(int x) { return x + 5; }
 
 struct AddFive {
     int operator()(int x) { return x + 5; };
 };
 
+class MoveOnlyAdd5 : SkNoncopyable {
+public:
+    MoveOnlyAdd5() {}
+    MoveOnlyAdd5(MoveOnlyAdd5&&) {}
+    MoveOnlyAdd5& operator=(MoveOnlyAdd5&&) { return *this; }
+
+    int operator()(int x) { return x + 5; }
+};
+
 DEF_TEST(Function, r) {
     // We should be able to turn a static function, an explicit functor, or a lambda
     // all into an SkFunction equally well.
-    test_add_five(r, SkFunction<int(int)>(&add_five));
-    test_add_five(r, SkFunction<int(int)>(AddFive()));
-    test_add_five(r, SkFunction<int(int)>([](int x) { return x + 5; }));
+    test_add_five(r, &add_five);
+    test_add_five(r, AddFive());
+    test_add_five(r, [](int x) { return x + 5; });
 
     // AddFive and the lambda above are both small enough to test small-object optimization.
     // Now test a lambda that's much too large for the small-object optimization.
     int a = 1, b = 1, c = 1, d = 1, e = 1;
-    test_add_five(r, SkFunction<int(int)>([&](int x) { return x + a + b + c + d + e; }));
-}
-
-DEF_TEST(Function_forwarding, r) {
-    class MoveOnlyAdd5 : SkNoncopyable {
-    public:
-        MoveOnlyAdd5() {}
-        MoveOnlyAdd5(MoveOnlyAdd5&&) {}
-        MoveOnlyAdd5& operator=(MoveOnlyAdd5&&) { return *this; }
-
-        int operator()(int x) { return x + 5; }
-    };
+    test_add_five(r, [&](int x) { return x + a + b + c + d + e; });
 
     // Makes sure we forward the functor when constructing SkFunction.
-    test_add_five(r, SkFunction<int(int)>(MoveOnlyAdd5()));
+    test_add_five(r, MoveOnlyAdd5());
 
     // Makes sure we forward arguments when calling SkFunction.
-    SkFunction<int(int, MoveOnlyAdd5&&, int)> b([](int x, MoveOnlyAdd5&& f, int y) {
+    REPORTER_ASSERT(r, [](int x, MoveOnlyAdd5&& f, int y) {
         return x * f(y);
-    });
-    REPORTER_ASSERT(r, b(2, MoveOnlyAdd5(), 4) == 18);
+    }(2, MoveOnlyAdd5(), 4) == 18);
 }