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, &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, [&](int x) { return x + a + b + c + d + e; });

    // Makes sure we forward the functor when constructing SkFunction.
    test_add_five(r, MoveOnlyAdd5());

    // Makes sure we forward arguments when calling SkFunction.
    SkFunction<int(int, MoveOnlyAdd5&&, int)> f([](int x, MoveOnlyAdd5&& addFive, int y) {
            return x * addFive(y);
    });
    REPORTER_ASSERT(r, f(2, MoveOnlyAdd5(), 4) == 18);
}