Error C2039: 'result_type': is not a member of the 'global namespace'
My application is throwing this error:
error C2039: 'result_type' : is not a member of '`global namespace''
for this code:
void handle_read_headers(const boost::system::error_code& err, RESTClient::response& resp)
{
if (!err)
{
// Process the response headers.
std::istream response_stream(&response_);
std::string header;
while (std::getline(response_stream, header) && header != "\r")
std::cout << header << "\n";
std::cout << "\n";
// Write whatever content we already have to output.
if (response_.size() > 0)
std::cout << &response_;
(&resp)->body = "Yehey!!!";
// Start reading remaining data until EOF.
boost::asio::async_read(socket_, response_,
boost::asio::transfer_at_least(1),
boost::bind(&client::handle_read_content, this,
boost::asio::placeholders::error, boost::ref(resp)));
}
else
{
std::cout << "Error: " << err << "\n";
}
}
The bound function looks like this:
void handle_read_content(const boost::system::error_code& err, RESTClient::response& resp){}
What could be wrong with my code?
Update:
I was able to compile the code with these changes
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According to this page of the ReadHandler documentation, you need to take both the error code and the number of bytes transferred.
Perhaps MSVC is more picky / sensitive about missing placeholders when invoking a binding expression .¹
Try adding the placeholder parameter to bind:
// Start reading remaining data until EOF.
boost::asio::async_read(socket_, response_,
boost::asio::transfer_at_least(1),
boost::bind(&client::handle_read_content, this,
boost::asio::placeholders::error,
boost::asio::placeholders::bytes_transferred,
boost::ref(resp)));
And obviously for the handler function itself:
void handle_read_content(const boost::system::error_code& ec, size_t bytes_transferred, RESTClient::response& resp){}
Update
I spent an unreasonable amount of effort (thanks @qballer, @nab and others live too!) To reproduce this in Visual Studio and got this:
For the record:
- Win32
- Boost 1_58_0
- OpenSSL-1.0.2c-i386-win32
- Visual Studio 2013 Update 4
¹ in fact, I've sometimes noticed that Asio accepts slightly different signatures for handler functions using GCC (my preferred compiler). I've always wondered if this is a feature or perhaps a bug?
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