| 1 | // Copyright (c) 2010 Lars Kielhorn |
|---|---|
| 2 | // Copyright (c) 2001-2010 Hartmut Kaiser |
| 3 | // |
| 4 | // Distributed under the Boost Software License, Version 1.0. (See accompanying |
| 5 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| 6 | |
| 7 | #include <boost/spirit/include/karma.hpp> |
| 8 | |
| 9 | #include <boost/core/lightweight_test.hpp> |
| 10 | |
| 11 | #include <iostream> |
| 12 | #include <string> |
| 13 | #include <iterator> |
| 14 | |
| 15 | namespace karma = boost::spirit::karma; |
| 16 | |
| 17 | // define a new real number formatting policy |
| 18 | template <typename Num> |
| 19 | struct scientific_policy : karma::real_policies<Num> |
| 20 | { |
| 21 | // we want the numbers always to be in scientific format |
| 22 | static int floatfield(Num) { return std::ios_base::scientific; } |
| 23 | }; |
| 24 | |
| 25 | int main() |
| 26 | { |
| 27 | // define a new generator type based on the new policy |
| 28 | typedef karma::real_generator<double, scientific_policy<double> > |
| 29 | science_type; |
| 30 | science_type const scientific = science_type(); |
| 31 | |
| 32 | std::string output; |
| 33 | typedef std::back_insert_iterator<std::string> output_iterator; |
| 34 | output_iterator sink(output); |
| 35 | |
| 36 | // should output: 1.0e-01, but will output: 10.0e-02 |
| 37 | BOOST_TEST(karma::generate(sink, scientific, 0.1) && output == "1.0e-01"); |
| 38 | |
| 39 | return boost::report_errors(); |
| 40 | } |
| 41 |