units-test.c++

// Copyright (c) 2013, Kenton Varda <temporal@gmail.com>
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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#include "units.h"
#include <gtest/gtest.h>
#include <iostream>

namespace kj {
namespace {

class Bytes;
class KiB;
class MiB;

typedef Quantity<int, Bytes> ByteCount;
typedef Quantity<int, KiB> KiBCount;
typedef Quantity<int, MiB> MiBCount;

constexpr ByteCount BYTE = unit<ByteCount>();
constexpr KiBCount KIB = unit<KiBCount>();
constexpr MiBCount MIB = unit<MiBCount>();

constexpr UnitRatio<int, Bytes, KiB> BYTES_PER_KIB = 1024 * BYTE / KIB;
constexpr UnitRatio<int, Bytes, MiB> BYTES_PER_MIB = 1024 * 1024 * BYTE / MIB;
constexpr auto KIB_PER_MIB = 1024 * KIB / MIB;

template <typename T, typename U>
std::ostream& operator<<(std::ostream& os, Quantity<T, U> value) {
  return os << (value / unit<Quantity<T, U>>());
}

TEST(UnitMeasure, Basics) {
  KiBCount k = 15 * KIB;
  EXPECT_EQ(15, k / KIB);
  EXPECT_EQ(16 * KIB, k + KIB);

  k += KIB;
  k *= 2048;

  EXPECT_EQ(32 * MIB, k / KIB_PER_MIB);

  EXPECT_TRUE(2 * KIB < 4 * KIB);
  EXPECT_FALSE(8 * KIB < 4 * KIB);
}

}  // namespace
}  // namespace kj