text: // The MIT License (MIT)
  //
  // Copyright (c) 2017 Howard Hinnant
  //
  // 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.
  
  // template <unsigned exp>
  // struct static_pow10
  // {
  //     static constepxr std::uint64_t value = ...;
  // };
  
  #include "date.h"
  
  #include <cassert>
  #include <sstream>
  #include <type_traits>
  
  int
  main()
  {
      using namespace date::detail;
      static_assert(static_pow10<0>::value ==  1, "");
      static_assert(static_pow10<1>::value ==  10, "");
      static_assert(static_pow10<2>::value ==  100, "");
      static_assert(static_pow10<3>::value ==  1000, "");
      static_assert(static_pow10<4>::value ==  10000, "");
      static_assert(static_pow10<5>::value ==  100000, "");
      static_assert(static_pow10<6>::value ==  1000000, "");
      static_assert(static_pow10<7>::value ==  10000000, "");
      static_assert(static_pow10<8>::value ==  100000000, "");
      static_assert(static_pow10<9>::value ==  1000000000, "");
      static_assert(static_pow10<10>::value == 10000000000, "");
  }
  