mp-units/example/hello_units.cpp

// The MIT License (MIT)
//
// Copyright (c) 2018 Mateusz Pusz
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
// !!! Before you commit any changes to this file please make sure to check if it !!!
// !!! renders correctly in the documentation "Examples" section.                 !!!
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

#include <mp-units/compat_macros.h>
#include <mp-units/ext/format.h>
#ifdef MP_UNITS_IMPORT_STD
import std;
#else
#include <iomanip>
#include <iostream>
#endif
#ifdef MP_UNITS_MODULES
import mp_units;
#else
#include <mp-units/systems/international.h>
#include <mp-units/systems/isq.h>
#include <mp-units/systems/si.h>
#endif

using namespace mp_units;

constexpr QuantityOf<isq::speed> auto avg_speed(QuantityOf<isq::length> auto d, QuantityOf<isq::time> auto t)
{
  return d / t;
}

int main()
{
  using namespace mp_units::si::unit_symbols;
  using namespace mp_units::international::unit_symbols;

  constexpr quantity v1 = 110 * km / h;
  constexpr quantity v2 = 70 * mph;
  constexpr quantity v3 = avg_speed(220. * km, 2 * h);
  constexpr quantity v4 = avg_speed(isq::distance(140. * mi), 2 * isq::duration[h]);
  constexpr quantity v5 = v3.in(m / s);
  constexpr quantity v6 = value_cast<m / s>(v4);
  constexpr quantity v7 = value_cast<int>(v6);

  std::cout << v1 << '\n';                                           // 110 km/h
  std::cout << std::setw(10) << std::setfill('*') << v2 << '\n';     // ***70 mi/h
  std::cout << MP_UNITS_STD_FMT::format("{:*^10}\n", v3);            // *110 km/h*
  std::cout << MP_UNITS_STD_FMT::format("{:%N in %U of %D}\n", v4);  // 70 in mi/h of LT⁻¹
  std::cout << MP_UNITS_STD_FMT::format("{::N[.2f]}\n", v5);         // 30.56 m/s
  std::cout << MP_UNITS_STD_FMT::format("{::N[.2f]U[dn]}\n", v6);    // 31.29 m⋅s⁻¹
  std::cout << MP_UNITS_STD_FMT::format("{:%N}\n", v7);              // 31
}