text: ﻿// Source encoding: utf-8  --  π is (or should be) a lowercase greek pi.
  #pragma once
  #include "~assert-is-c++17-or-later.hpp"
  
  // Copyright (c) 2020 Alf P. Steinbach. MIT license, with license text:
  //
  // 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.
  
  #if defined( __clang__ )
  # // Need to exclude clang explicitly because it pretends to be both Visual C++ and g++.
  #elif defined( _MSC_VER ) && !defined( KS_ASSUME_BOOLEAN_OPERATOR_NAMES_PLEASE )
  #   if _MSC_VER < 1911  // Visual Studio 2017 version 15.3, assumed "/permissive-" intro.
  #       ifndef and
              static_assert( false,
                  "Requires standard boolean keywords like `and`. For MSVC use e.g."
                  " `/std:c++17 /Zc:__cplusplus /FI\"iso646.h\" /EHsc /wd4459 /utf-8`."
                  );
  #           include <because.requires_standard_boolean_keywords>
  #       endif
  #   endif
  #endif
  