/* * Copyright (c) 2017, 2021, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "memory/allStatic.hpp" #include "metaprogramming/enableIf.hpp" #include "utilities/debug.hpp" #include "unittest.hpp" #include <type_traits> class EnableIfTest: AllStatic { class A: AllStatic { public: template <bool condition> static typename EnableIf<condition, char>::type test(); template <bool condition> static typename EnableIf<!condition, long>::type test(); }; static const bool A_test_true_is_char = sizeof(A::test<true>()) == sizeof(char); STATIC_ASSERT(A_test_true_is_char); static const bool A_test_false_is_long = sizeof(A::test<false>()) == sizeof(long); STATIC_ASSERT(A_test_false_is_long); }; template<typename T, ENABLE_IF(std::is_integral<T>::value)> static T sub1(T x) { return x - 1; } TEST(TestEnableIf, one_decl_and_def) { EXPECT_EQ(15, sub1(16)); } template<typename T, ENABLE_IF(std::is_integral<T>::value)> static T sub2(T x); template<typename T, ENABLE_IF_SDEFN(std::is_integral<T>::value)> T sub2(T x) { return x - 2; } TEST(TestEnableIf, separate_decl_and_def) { EXPECT_EQ(14, sub2(16)); } template<typename T> struct TestEnableIfNested { template<typename U, ENABLE_IF(std::is_integral<U>::value)> static U sub1(U x); }; template<typename T> template<typename U, ENABLE_IF_SDEFN(std::is_integral<U>::value)> U TestEnableIfNested<T>::sub1(U x) { return x - 1; } TEST(TestEnableIf, nested_separate_decl_and_def) { EXPECT_EQ(15, TestEnableIfNested<void>::sub1(16)); } // Demonstrate workaround for non-dependent condition. template<typename T> struct TestEnableIfNonDependent { // Dependent is used to make the ENABLE_IF condition dependent on // the type parameters for this function. template<typename Dependent = T, ENABLE_IF(std::is_same<int, Dependent>::value)> static T value() { return T{}; } static int instantiate() { return 5; } }; TEST(TestEnableIf, non_dependent) { EXPECT_EQ(int{}, TestEnableIfNonDependent<int>::value()); // This fails to compile if the ENABLE_IF for value() directly uses // T rather than indirectly via Dependent. EXPECT_EQ(5, TestEnableIfNonDependent<void>::instantiate()); }