Beast: questions about beast::websocket::close_reason

[vchang-akamai]

1) I noticed these two constructors for beast::websocket::close_reason:

    /// Construct from a code.
    close_reason(std::uint16_t code_)
        : code(code_)
    {
    }

    /// Construct from a code and reason.
    template<std::size_t N>
    close_reason(close_code code_,
            char const (&reason_)[N])
        : code(code_)
        , reason(reason_)
    {
    }

There seems to be an inconsistency for the "code_" parameter. The first one uses uint16_t for code_ while the second one uses close_code for code_. close_code is an enum, so that's signed integer.

2) Two of the constructors take a 'char const (&)[N]' for the reason_ parameter. Would be possible to provide a std::string version as well?

[vinniefalco]

Hmm, you are right. They should both use a regular integer, probably unsigned since thats what the WebSocket protocol specifies.

I don't think std::string is a particularly good choice of parameter but beast::string_view would be an improvement, and it would still let you pass a std::string (string_view is constructible from std::string).

These are good observations, thanks! I will make these changes.

[chreniuc]

@vinniefalco

How does one provide a custom close code(user defined, just like the websocket specs say, range 4000-4999) and a close reason in the async_close method?

Doing this:

close_reason = make_shared<::boost::beast::websocket::close_reason>(
        static_cast<::std::uint16_t>(4001 ), "Close reason."s ) 

ws.async_close(
    *close_reason ,
    std::bind( &ws_server::on_close_websocket, this, conn_ptr, close_reason,
      std::placeholders::_1 ) );

I get a compile error:

error: invalid conversion from ‘short unsigned int’ to ‘boost::beast::websocket::close_code’ [-fpermissive]

But creating the close_reason with ony the close_code works:

close_reason = make_shared<::boost::beast::websocket::close_reason>(
        static_cast<::std::uint16_t>(4001 ) ) 

ws.async_close(
    *close_reason ,
    std::bind( &ws_server::on_close_websocket, this, conn_ptr, close_reason,
      std::placeholders::_1 ) );

The first method calls this constructor:

close_reason(close_code code_, string_view s)

Where close_code is this enum:

enum close_code : std::uint16_t
{
    /// Normal closure; the connection successfully completed whatever purpose for which it was created.
    normal          = 1000
 //....
}

And the second method calls this constructor:

 close_reason(std::uint16_t code_)

Shouldn't we be able to use custom close codes and close reasons?

[chreniuc]

I forgot to mention the boost version: it's 1.70.0

[vinniefalco]

cast to a close code not a uint16_t

[ceaglest]

Thank you, this issue was also helpful for me to understand how to provide a custom beast::websocket::close_reason.