ceph/src/boost/libs/safe_numerics/example/safe_format.hpp

   1 //  Copyright (c) 2018 Robert Ramey
   2 //
   3 // Distributed under the Boost Software License, Version 1.0. (See
   4 // accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #ifndef BOOST_SAFE_FORMAT_HPP
   8 #define BOOST_SAFE_FORMAT_HPP
   9
  10 //  Copyright (c) 2015 Robert Ramey
  11 //
  12 // Distributed under the Boost Software License, Version 1.0. (See
  13 // accompanying file LICENSE_1_0.txt or copy at
  14 // http://www.boost.org/LICENSE_1_0.txt)
  15
  16 #include <ostream>
  17 #include <typeinfo>
  18
  19 #include <boost/core/demangle.hpp>
  20 #include <boost/safe_numerics/safe_common.hpp>
  21
  22 namespace {
  23
  24 // create an output manipulator which prints variable type and limits
  25 // as well as value
  26 template<typename T>
  27 struct safe_format_impl {
  28     const T & m_t;
  29     safe_format_impl(const T & t) :
  30         m_t(t)
  31     {}
  32     template <class charT, class Traits>
  33     friend std::basic_ostream<charT,Traits> &
  34     operator<<(
  35         std::basic_ostream<charT,Traits> & os,
  36         const safe_format_impl<T> & f
  37     ){
  38         return os
  39             << "<"
  40             << boost::core::demangle(typeid(
  41                 typename boost::safe_numerics::base_type<T>::type
  42                 ).name()
  43             )
  44             << ">["
  45             << std::numeric_limits<T>::min() << ","
  46             << std::numeric_limits<T>::max() << "] = "
  47             << f.m_t;
  48     }
  49 };
  50
  51 } // anonymous namespace
  52
  53 template<typename T>
  54 auto safe_format(const T & t){
  55     return safe_format_impl<T>(t);
  56 }
  57
  58 #endif // BOOST_SAFE_FORMAT_HPP