1/*=============================================================================
2 Copyright (c) 2001-2014 Joel de Guzman
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#if !defined(BOOST_SPIRIT_X3_REAL_APRIL_18_2006_0850AM)
8#define BOOST_SPIRIT_X3_REAL_APRIL_18_2006_0850AM
9
10#include <boost/spirit/home/x3/core/parser.hpp>
11#include <boost/spirit/home/x3/core/skip_over.hpp>
12#include <boost/spirit/home/x3/numeric/real_policies.hpp>
13#include <boost/spirit/home/x3/support/numeric_utils/extract_real.hpp>
14
15namespace boost { namespace spirit { namespace x3
16{
17 template <typename T, typename RealPolicies = real_policies<T> >
18 struct real_parser : parser<real_parser<T, RealPolicies> >
19 {
20 typedef T attribute_type;
21 static bool const has_attribute = true;
22
23 constexpr real_parser()
24 : policies() {}
25
26 constexpr real_parser(RealPolicies const& policies)
27 : policies(policies) {}
28
29 template <typename Iterator, typename Context>
30 bool parse(Iterator& first, Iterator const& last
31 , Context const& context, unused_type, T& attr_) const
32 {
33 x3::skip_over(first, last, context);
34 return extract_real<T, RealPolicies>::parse(first, last, attr_, policies);
35 }
36
37 template <typename Iterator, typename Context, typename Attribute>
38 bool parse(Iterator& first, Iterator const& last
39 , Context const& context, unused_type, Attribute& attr_param) const
40 {
41 // this case is called when Attribute is not T
42 T attr_;
43 if (parse(first, last, context, unused, attr_))
44 {
45 traits::move_to(attr_, attr_param);
46 return true;
47 }
48 return false;
49 }
50
51 RealPolicies policies;
52 };
53
54 typedef real_parser<float> float_type;
55 constexpr float_type float_ = {};
56
57 typedef real_parser<double> double_type;
58 constexpr double_type double_ = {};
59
60 typedef real_parser<long double> long_double_type;
61 constexpr long_double_type long_double = {};
62
63}}}
64
65#endif
66

source code of boost/libs/spirit/include/boost/spirit/home/x3/numeric/real.hpp