core.h

/* -*- Mode: C++; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
 *     Copyright 2016 Couchbase, Inc
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */

#pragma once

#include <cstddef>
#include <type_traits>

#include "visibility.h"

#if defined(__GNUC__) || defined(__clang__)

#define likely(x) __builtin_expect(!!(x), 1)

#define unlikely(x) __builtin_expect(!!(x), 0)
#else
#define likely(x) (x)
#define unlikely(x) (x)
#endif

namespace phosphor {
    // Introducing cross-platform ssize_t (doesn't exist on windows)
    // as future-proofing if e.g. negative statistics are ever needed
    using ssize_t = std::make_signed<size_t>::type;
}