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/*
* 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());
}
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