// Boost.Units - A C++ library for zero-overhead dimensional analysis and // unit/quantity manipulation and conversion // // Copyright (C) 2003-2008 Matthias Christian Schabel // Copyright (C) 2008 Steven Watanabe // // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) #include #include #include #include #include #include #include //[runtime_unit_snippet_1 namespace { using namespace boost::units; using imperial::foot_base_unit; std::map > known_units; } quantity calculate(const quantity& t) { return(boost::units::hypot(t, 2.0 * si::meters)); } int main() { known_units["meter"] = 1.0 * si::meters; known_units["centimeter"] = .01 * si::meters; known_units["foot"] = conversion_factor(foot_base_unit::unit_type(), si::meter) * si::meter; std::string output_type("meter"); std::string input; while((std::cout << "> ") && (std::cin >> input)) { if(!input.empty() && input[0] == '#') { std::getline(std::cin, input); } else if(input == "exit") { break; } else if(input == "help") { std::cout << "type \"exit\" to exit\n" "type \"return 'unit'\" to set the return units\n" "type \"'number' 'unit'\" to do a simple calculation" << std::endl; } else if(input == "return") { if(std::cin >> input) { if(known_units.find(input) != known_units.end()) { output_type = input; std::cout << "Done." << std::endl; } else { std::cout << "Unknown unit \"" << input << "\"" << std::endl; } } else { break; } } else { try { double value = boost::lexical_cast(input); if(std::cin >> input) { if(known_units.find(input) != known_units.end()) { std::cout << static_cast( calculate(value * known_units[input]) / known_units[output_type]) << ' ' << output_type << std::endl; } else { std::cout << "Unknown unit \"" << input << "\"" << std::endl; } } else { break; } } catch(...) { std::cout << "Input error" << std::endl; } } } } //]