ceph/src/boost/boost/convert/printf.hpp

   1 // Copyright (c) 2009-2016 Vladimir Batov.
   2 // Use, modification and distribution are subject to the Boost Software License,
   3 // Version 1.0. See http://www.boost.org/LICENSE_1_0.txt.
   4
   5 #ifndef BOOST_CONVERT_PRINTF_HPP
   6 #define BOOST_CONVERT_PRINTF_HPP
   7
   8 #include <boost/convert/base.hpp>
   9 #include <boost/make_default.hpp>
  10 #include <boost/mpl/vector.hpp>
  11 #include <boost/mpl/find.hpp>
  12 #include <boost/range/as_literal.hpp>
  13 #include <string>
  14 #include <cstdio>
  15
  16 namespace boost { namespace cnv
  17 {
  18     struct printf;
  19 }}
  20
  21 struct boost::cnv::printf : public boost::cnv::cnvbase<boost::cnv::printf>
  22 {
  23     typedef boost::cnv::printf             this_type;
  24     typedef boost::cnv::cnvbase<this_type> base_type;
  25
  26     using base_type::operator();
  27
  28     template<typename in_type>
  29     cnv::range<char*>
  30     to_str(in_type value_in, char* buf) const
  31     {
  32         char const*     fmt = pformat(pos<in_type>());
  33         int const num_chars = snprintf(buf, bufsize_, fmt, precision_, value_in);
  34         bool const  success = num_chars < bufsize_;
  35
  36         return cnv::range<char*>(buf, success ? (buf + num_chars) : buf);
  37     }
  38     template<typename string_type, typename out_type>
  39     void
  40     str_to(cnv::range<string_type> range, optional<out_type>& result_out) const
  41     {
  42         out_type    result = boost::make_default<out_type>();
  43         int const num_read = sscanf(&*range.begin(), format(pos<out_type>()), &result);
  44
  45         if (num_read == 1)
  46             result_out = result;
  47     }
  48
  49     private:
  50
  51     template<typename Type> int pos() const
  52     {
  53         typedef boost::mpl::vector<double, float,
  54                                    int, unsigned int,
  55                                    short int, unsigned short int,
  56                                    long int, unsigned long int
  57                                    > managed_types;
  58
  59         typedef typename boost::mpl::find<managed_types, Type>::type type_iterator;
  60         typedef typename type_iterator::pos                               type_pos;
  61
  62         return type_pos::value;
  63     }
  64
  65     char const* pformat(int pos) const
  66     {
  67         static char const* d_format[] = { "%.*f", "%.*f", "%.*d", "%.*u", "%.*hd", "%.*hu", "%.*ld", "%.*lu" }; // Must match managed_types
  68         static char const* x_format[] = { "%.*f", "%.*f", "%.*x", "%.*x", "%.*hx", "%.*hx", "%.*lx", "%.*lx" }; // Must match managed_types
  69         static char const* o_format[] = { "%.*f", "%.*f", "%.*o", "%.*o", "%.*ho", "%.*ho", "%.*lo", "%.*lo" }; // Must match managed_types
  70         char const*            format = base_ == 10 ? d_format[pos]
  71                                       : base_ == 16 ? x_format[pos]
  72                                       : base_ ==  8 ? o_format[pos]
  73                                       : (BOOST_ASSERT(0), (char const*) 0);
  74         return format;
  75     }
  76     char const* format(int pos) const
  77     {
  78         static char const* d_format[] = { "%f", "%f", "%d", "%u", "%hd", "%hu", "%ld", "%lu" }; // Must match managed_types
  79         static char const* x_format[] = { "%f", "%f", "%x", "%x", "%hx", "%hx", "%lx", "%lx" }; // Must match managed_types
  80         static char const* o_format[] = { "%f", "%f", "%o", "%o", "%ho", "%ho", "%lo", "%lo" }; // Must match managed_types
  81         char const*            format = base_ == 10 ? d_format[pos]
  82                                       : base_ == 16 ? x_format[pos]
  83                                       : base_ ==  8 ? o_format[pos]
  84                                       : (BOOST_ASSERT(0), (char const*) 0);
  85         return format;
  86     }
  87 };
  88
  89 #endif // BOOST_CONVERT_PRINTF_HPP