text: // 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
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  // SOFTWARE.
  
  #pragma once
  
  #include <units/physical/dimensions.h>
  #include <units/physical/si/force.h>
  #include <units/physical/si/prefixes.h>
  #include <units/quantity.h>
  
  namespace units::si {
  
  struct joule : named_unit<joule, "J", prefix> {};
  struct millijoule : prefixed_unit<millijoule, milli, joule> {};
  struct kilojoule : prefixed_unit<kilojoule, kilo, joule> {};
  struct megajoule : prefixed_unit<megajoule, mega, joule> {};
  struct gigajoule : prefixed_unit<gigajoule, giga, joule> {};
  
  struct electronvolt : named_scaled_unit<electronvolt, "eV", no_prefix, ratio<1'602'176'634, 1'000'000'000, -19>, joule> {};
  
  struct dim_energy : physical::dim_energy<dim_energy, joule, dim_force, dim_length> {};
  
  template<Unit U, Scalar Rep = double>
  using energy = quantity<dim_energy, U, Rep>;
  
  inline namespace literals {
  
  // J
  constexpr auto operator""_J(unsigned long long l) { return energy<joule, std::int64_t>(l); }
  constexpr auto operator""_J(long double l) { return energy<joule, long double>(l); }
  
  // mJ
  constexpr auto operator""mJ(unsigned long long l) { return energy<millijoule, std::int64_t>(l); }
  constexpr auto operator""mJ(long double l) { return energy<millijoule, long double>(l); }
  
  // kJ
  constexpr auto operator""kJ(unsigned long long l) { return energy<kilojoule, std::int64_t>(l); }
  constexpr auto operator""kJ(long double l) { return energy<kilojoule, long double>(l); }
  
  // MJ
  constexpr auto operator""MJ(unsigned long long l) { return energy<megajoule, std::int64_t>(l); }
  constexpr auto operator""MJ(long double l) { return energy<megajoule, long double>(l); }
  
  // GJ
  constexpr auto operator""GJ(unsigned long long l) { return energy<gigajoule, std::int64_t>(l); }
  constexpr auto operator""GJ(long double l) { return energy<gigajoule, long double>(l); }
  
  // eV
  constexpr auto operator""eV(unsigned long long l) { return energy<electronvolt, std::int64_t>(l); }
  constexpr auto operator""eV(long double l) { return energy<electronvolt, long double>(l); }
  
  }  // namespace literals
  
  }  // namespace units::si
  