/*

 * Copyright (c) 2017, 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.

 *

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 */

#ifndef SHARE_VM_METAPROGRAMMING_ENABLEIF_HPP

#define SHARE_VM_METAPROGRAMMING_ENABLEIF_HPP

#include "memory/allocation.hpp"

// This metaprogramming tool allows explicitly enabling and disabling overloads

// of member functions depending on whether the condition B holds true.

// For example typename EnableIf<IsPointer<T>::value>::type func(T ptr) would

// only become an overload the compiler chooses from if the type T is a pointer.

// If it is not, then the template definition is not expanded and there will be

// no compiler error if there is another overload of func that is selected when

// T is not a pointer. Like for example

// typename EnableIf<!IsPointer<T>::value>::type func(T not_ptr)

template <bool B, typename T = void>

struct EnableIf: AllStatic {};

template <typename T>

struct EnableIf<true, T>: AllStatic {

  typedef T type;

};

#endif // SHARE_VM_METAPROGRAMMING_ENABLEIF_HPP