ceph/src/boost/libs/lexical_cast/example/small_examples.cpp

   1 // Copyright Antony Polukhin, 2013-2020.
   2
   3 // Distributed under the Boost Software License, Version 1.0.
   4 // (See the accompanying file LICENSE_1_0.txt
   5 // or a copy at <http://www.boost.org/LICENSE_1_0.txt>.)
   6
   7 #include <boost/lexical_cast.hpp>
   8 #include <string>
   9 #include <cstdio>
  10
  11 #ifdef BOOST_MSVC
  12 #  pragma warning(disable: 4996) // `strerror` is not safe
  13 #endif
  14
  15 //[lexical_cast_log_errno
  16 //`The following example uses numeric data in a string expression:
  17
  18 void log_message(const std::string &);
  19
  20 void log_errno(int yoko)
  21 {
  22     log_message("Error " + boost::lexical_cast<std::string>(yoko) + ": " + strerror(yoko));
  23 }
  24
  25 //] [/lexical_cast_log_errno]
  26
  27
  28 //[lexical_cast_fixed_buffer
  29 //`The following example converts some number and puts it to file:
  30
  31 void number_to_file(int number, std::FILE* file)
  32 {
  33     typedef boost::array<char, 50> buf_t; // You can use std::array if your compiler supports it
  34     buf_t buffer = boost::lexical_cast<buf_t>(number); // No dynamic memory allocation
  35     std::fputs(buffer.begin(), file);
  36 }
  37
  38 //] [/lexical_cast_fixed_buffer]
  39
  40 //[lexical_cast_substring_conversion
  41 //`The following example takes part of the string and converts it to `int`:
  42
  43 int convert_strings_part(const std::string& s, std::size_t pos, std::size_t n)
  44 {
  45     return boost::lexical_cast<int>(s.data() + pos, n);
  46 }
  47
  48 //] [/lexical_cast_substring_conversion]
  49
  50 void log_message(const std::string &) {}
  51
  52 int main()
  53 {
  54     return 0;
  55 }
  56