[Boost-bugs] [Boost C++ Libraries] #13291: read_until won't compile with Visual Studio 2017 using regex

Subject: [Boost-bugs] [Boost C++ Libraries] #13291: read_until won't compile with Visual Studio 2017 using regex
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2017-11-09 10:10:57

#13291: read_until won't compile with Visual Studio 2017 using regex
---------------------------------------------+----------------------------
 Reporter:  Ville-Pekka Vahteala <vahtis@…>  |      Owner:  chris_kohlhoff
     Type:  Bugs                             |     Status:  new
Milestone:  To Be Determined                 |  Component:  asio
  Version:  Boost 1.66.0                     |   Severity:  Showstopper
 Keywords:  asio, regex                      |
---------------------------------------------+----------------------------
 Compiling following code will produce compiler error
 {{{
 #include <boost/asio/io_service.hpp>
 #include <boost/asio/ip/tcp.hpp>
 #include <boost/asio/read_until.hpp>
 #include <boost/asio/streambuf.hpp>
 #include <boost/regex.hpp>

 int main() {
         boost::asio::io_service ios;
         boost::asio::ip::tcp::socket s(ios);
         boost::asio::streambuf b;
         boost::system::error_code e;
         boost::asio::read_until(s, b, boost::regex("i am just a regex"),
 e);
 }
 }}}

 {{{
 1>d:\source\boost\boost\asio\impl\read_until.hpp(273): error C2664:
 'size_t
 boost::asio::basic_streambuf<std::allocator<char>>::read_size_helper(boost::asio::basic_streambuf<std::allocator<char>>
 &,::size_t)': cannot convert argument 1 from
 'boost::asio::basic_streambuf_ref<Allocator>' to
 'boost::asio::basic_streambuf<std::allocator<char>> &'
 1>        with
 1>        [
 1>            Allocator=std::allocator<char>
 1>        ]
 1>d:\source\boost\boost\asio\impl\read_until.hpp(404): note: see reference
 to function template instantiation 'size_t
 boost::asio::read_until<SyncReadStream,boost::asio::basic_streambuf_ref<Allocator>>(SyncReadStream
 &,DynamicBuffer &&,const boost::regex &,boost::system::error_code &)'
 being compiled
 1>        with
 1>        [
 1>            SyncReadStream=boost::asio::ip::tcp::socket,
 1>            Allocator=std::allocator<char>,
 1>
 DynamicBuffer=boost::asio::basic_streambuf_ref<std::allocator<char>>
 1>        ]
 1>c:\users\????\error.cpp(12): note: see reference to function template
 instantiation 'size_t
 boost::asio::read_until<boost::asio::ip::tcp::socket,std::allocator<char>>(SyncReadStream
 &,boost::asio::basic_streambuf<std::allocator<char>> &,const boost::regex
 &,boost::system::error_code &)' being compiled
 1>        with
 1>        [
 1>            SyncReadStream=boost::asio::ip::tcp::socket
 1>        ]
 }}}

 This can be solved by using same calculation as other methods use

 {{{
     // Need more data.
         std::size_t bytes_to_read = std::min<std::size_t>(
                 std::max<std::size_t>(512, b.capacity() - b.size()),
                 std::min<std::size_t>(65536, b.max_size() - b.size()));

 }}}

 instead of

 {{{
     std::size_t bytes_to_read = read_size_helper(b, 65536);

 }}}

-- 
Ticket URL: <https://svn.boost.org/trac10/boost/ticket/13291>
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