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Why is there no boost::copy_on_write_ptr?


Why is there no boost::copy_on_write_ptr?

By : jimjar
Date : October 21 2020, 11:12 AM
around this issue There was a lot of debate over the possibility, and at least one suggested version of what eventually came out as auto_ptr was for a reference counted COW pointer.
Unfortunately, the time for COW has mostly passed. Making a COW pointer (or COW-whatever) thread-safe can introduce serious performance problems.
code :


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Boost linker error: Unresolved external symbol "class boost::system::error_category const & __cdecl boost::syst

Boost linker error: Unresolved external symbol "class boost::system::error_category const & __cdecl boost::syst


By : lannie1980
Date : March 29 2020, 07:55 AM
around this issue I solved the problem. I had built 32-bit libraries when I had intended to build 64-bit libraries. I fixed up my build statement, and built 64-bit libraries, and now it works.
Here is my bjam command line:
code :
C:\Program Files (x86)\boost\boost_1_38>bjam --build-dir=c:\boost --build-type=complete --toolset=msvc-9.0 address-model=64 architecture=x86 --with-system
Intellisense shows boost::boost::boost::boost::boost::boost::classname....... why?

Intellisense shows boost::boost::boost::boost::boost::boost::classname....... why?


By : user1505227
Date : March 29 2020, 07:55 AM
wish help you to fix your issue I have some C++ code, and for some reason, for a couple of classes, they show up as boost::boost::boost::boost::boost::classname in the Visual Studio browser. , I installed boost 1.40 instead of 1.39, and the problem went away.
Problem with boost::find_format_all, boost::regex_finder and custom regex formatter (bug boost 1.42)

Problem with boost::find_format_all, boost::regex_finder and custom regex formatter (bug boost 1.42)


By : artur bradman
Date : March 29 2020, 07:55 AM
may help you . The struct find_regexF seems to be the culprit. As you can see, it returns an empty result with a uninitialized match_results(). Looking through SO found me the following solution:
code :
struct custom_formatter()
{

  template< typename T >
  std::string operator()( const T & s ) const
  {
      std::string matchStr;
      for (typename T::const_iterator i = Match.begin();
             i != Match.end();
             i++) {
          // perform substitutions via *i
      }
      return matchStr;
  }

}
template<typename InputIteratorT>
std::string operator()( 
    const regex_search_result<InputIteratorT>& Replace ) const
{
    if ( Replace.empty() )
    {
        return std::string();
    }
    else
    {
        std::string matchStr = s.match_results().str(1);
        // perform substitutions
        return matchStr;      
    }
}
Copy constructor not called when using boost::bind, boost::shared_ptr, and boost::thread together

Copy constructor not called when using boost::bind, boost::shared_ptr, and boost::thread together


By : user2516878
Date : March 29 2020, 07:55 AM
should help you out It seems your copy constructor is flawed. You're copying from your empty vector to your vector. Which results in nothing being copied.
I think you mean:
code :
for (it = (workflow->_tasks).begin(); it < (workflow->_tasks).end(); it++)
    (this->_tasks).push_back(*it);
Transform a std::vector of boost.asio::ip::address via boost::algorithm::join and boost::adaptors::transformed

Transform a std::vector of boost.asio::ip::address via boost::algorithm::join and boost::adaptors::transformed


By : Thus0
Date : March 29 2020, 07:55 AM
will help you to_string has overloads, so you need to specify which one you want (use a static_cast)
code :
boost::algorithm::join(
        addresses | 
        transformed(std::mem_fn(static_cast<std::string (address_v4::*)() const>(&boost::asio::ip::address_v4::to_string))), ", ");
boost::algorithm::join(
        addresses | 
        transformed([](address_v4 const& a) { return a.to_string(); }), ", ");
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