// Copyright (c) 2001-2011 Hartmut Kaiser
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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#if !defined(BOOST_SPIRIT_KARMA_BOOL_POLICIES_SEP_28_2009_1203PM)
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#define BOOST_SPIRIT_KARMA_BOOL_POLICIES_SEP_28_2009_1203PM
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#if defined(_MSC_VER)
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#pragma once
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#endif
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#include <boost/spirit/home/support/char_class.hpp>
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#include <boost/spirit/home/karma/generator.hpp>
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#include <boost/spirit/home/karma/char.hpp>
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#include <boost/spirit/home/karma/numeric/detail/numeric_utils.hpp>
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namespace boost { namespace spirit { namespace karma
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{
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///////////////////////////////////////////////////////////////////////////
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//
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// bool_policies, if you need special handling of your boolean output
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// just overload this policy class and use it as a template
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// parameter to the karma::bool_generator boolean generator
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//
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// struct special_bool_policy : karma::bool_policies<>
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// {
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// // we want to spell the names of false as eurt (true backwards)
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// template <typename CharEncoding, typename Tag
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// , typename OutputIterator>
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// static bool generate_false(OutputIterator& sink, bool)
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// {
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// return string_inserter<CharEncoding, Tag>::call(sink, "eurt");
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// }
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// };
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//
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// typedef karma::bool_generator<special_bool_policy> backwards_bool;
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//
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// karma::generate(sink, backwards_bool(), false); // will output: eurt
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//
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///////////////////////////////////////////////////////////////////////////
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template <typename T = bool>
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struct bool_policies
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{
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///////////////////////////////////////////////////////////////////////
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// Expose the data type the generator is targeted at
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///////////////////////////////////////////////////////////////////////
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typedef T value_type;
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///////////////////////////////////////////////////////////////////////
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// By default the policy doesn't require any special iterator
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// functionality. The boolean generator exposes its properties
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// from here, so this needs to be updated in case other properties
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// need to be implemented.
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///////////////////////////////////////////////////////////////////////
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typedef mpl::int_<generator_properties::no_properties> properties;
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///////////////////////////////////////////////////////////////////////
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// This is the main function used to generate the output for a
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// boolean. It is called by the boolean generator in order
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// to perform the conversion. In theory all of the work can be
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// implemented here, but it is the easiest to use existing
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// functionality provided by the type specified by the template
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// parameter `Inserter`.
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//
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// sink: the output iterator to use for generation
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// n: the floating point number to convert
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// p: the instance of the policy type used to instantiate this
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// floating point generator.
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///////////////////////////////////////////////////////////////////////
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template <typename Inserter, typename OutputIterator, typename Policies>
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static bool
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call (OutputIterator& sink, T n, Policies const& p)
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{
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return Inserter::call_n(sink, n, p);
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}
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///////////////////////////////////////////////////////////////////////
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// Print the textual representations of a true boolean value
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//
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// sink The output iterator to use for generation
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// b The boolean value to convert.
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//
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// The CharEncoding and Tag template parameters are either of the type
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// unused_type or describes the character class and conversion to be
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// applied to any output possibly influenced by either the lower[...]
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// or upper[...] directives.
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//
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///////////////////////////////////////////////////////////////////////
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template <typename CharEncoding, typename Tag, typename OutputIterator>
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static bool generate_true(OutputIterator& sink, T)
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{
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return string_inserter<CharEncoding, Tag>::call(sink, "true");
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}
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///////////////////////////////////////////////////////////////////////
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// Print the textual representations of a false boolean value
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//
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// sink The output iterator to use for generation
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// b The boolean value to convert.
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//
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// The CharEncoding and Tag template parameters are either of the type
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// unused_type or describes the character class and conversion to be
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// applied to any output possibly influenced by either the lower[...]
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// or upper[...] directives.
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//
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///////////////////////////////////////////////////////////////////////
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template <typename CharEncoding, typename Tag, typename OutputIterator>
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static bool generate_false(OutputIterator& sink, T)
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{
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return string_inserter<CharEncoding, Tag>::call(sink, "false");
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}
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};
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}}}
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#endif
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