asio/impl/config.hpp

0001 //
0002 // impl/config.hpp
0003 // ~~~~~~~~~~~~~~~
0004 //
0005 // Copyright (c) 2003-2025 Christopher M. Kohlhoff (chris at kohlhoff dot com)
0006 //
0007 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0008 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0009 //
0010
0011 #ifndef BOOST_ASIO_IMPL_CONFIG_HPP
0012 #define BOOST_ASIO_IMPL_CONFIG_HPP
0013
0014 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
0015 # pragma once
0016 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
0017
0018 #include <boost/asio/detail/config.hpp>
0019 #include <cerrno>
0020 #include <cstdlib>
0021 #include <limits>
0022 #include <stdexcept>
0023
0024 #include <boost/asio/detail/push_options.hpp>
0025
0026 namespace boost {
0027 namespace asio {
0028 namespace detail {
0029
0030 template <typename T>
0031 T config_get(const config_service& service, const char* section,
0032     const char* key, T default_value, false_type /*is_bool*/)
0033 {
0034   if (is_unsigned<T>::value)
0035   {
0036     char buf[std::numeric_limits<unsigned long long>::digits10
0037         + 1 /* sign */ + 1 /* partial digit */ + 1 /* NUL */];
0038     if (const char* str = service.get_value(section, key, buf, sizeof(buf)))
0039     {
0040       char* end = nullptr;
0041       errno = 0;
0042       unsigned long long result = std::strtoull(str, &end, 0);
0043       if (errno == ERANGE
0044           || result > static_cast<unsigned long long>(
0045             (std::numeric_limits<T>::max)()))
0046         detail::throw_exception(std::out_of_range("config out of range"));
0047       return static_cast<T>(result);
0048     }
0049   }
0050   else
0051   {
0052     char buf[std::numeric_limits<unsigned long long>::digits10
0053         + 1 /* sign */ + 1 /* partial digit */ + 1 /* NUL */];
0054     if (const char* str = service.get_value(section, key, buf, sizeof(buf)))
0055     {
0056       char* end = nullptr;
0057       errno = 0;
0058       long long result = std::strtoll(str, &end, 0);
0059       if (errno == ERANGE || result < (std::numeric_limits<T>::min)()
0060           || result > (std::numeric_limits<T>::max)())
0061         detail::throw_exception(std::out_of_range("config out of range"));
0062       return static_cast<T>(result);
0063     }
0064   }
0065   return default_value;
0066 }
0067
0068 template <typename T>
0069 T config_get(const config_service& service, const char* section,
0070     const char* key, T default_value, true_type /*is_bool*/)
0071 {
0072   char buf[std::numeric_limits<unsigned long long>::digits10
0073       + 1 /* sign */ + 1 /* partial digit */ + 1 /* NUL */];
0074   if (const char* str = service.get_value(section, key, buf, sizeof(buf)))
0075   {
0076     char* end = nullptr;
0077     errno = 0;
0078     unsigned long long result = std::strtoll(str, &end, 0);
0079     if (errno == ERANGE || (result != 0 && result != 1))
0080       detail::throw_exception(std::out_of_range("config out of range"));
0081     return static_cast<T>(result != 0);
0082   }
0083   return default_value;
0084 }
0085
0086 } // namespace detail
0087
0088 template <typename T>
0089 constraint_t<is_integral<T>::value, T>
0090 config::get(const char* section, const char* key, T default_value) const
0091 {
0092   return detail::config_get(service_, section,
0093       key, default_value, is_same<T, bool>());
0094 }
0095
0096 } // namespace asio
0097 } // namespace boost
0098
0099 #include <boost/asio/detail/pop_options.hpp>
0100
0101 #endif // BOOST_ASIO_IMPL_CONFIG_HPP