BOOST_THROW_EXCEPTION does not support inserting additional errinfo

[sdebionne]

AFAIU from the documentation that defines BOOST_THROW_EXCEPTION as

#define BOOST_THROW_EXCEPTION(x)\
        ::boost::throw_exception( ::boost::enable_error_info(x) <<\
        ::boost::throw_function(BOOST_THROW_EXCEPTION_CURRENT_FUNCTION) <<\
        ::boost::throw_file(__FILE__) <<\
        ::boost::throw_line((int)__LINE__) )

it should be possible to write

#include <boost/exception/errinfo_errno.hpp>
#include <boost/throw_exception.hpp>

BOOST_THROW_EXCEPTION(std::runtime_error("oupsy")) << boost::errinfo_errno(res);

But looking at the current implementation of BOOST_THROW_EXCEPTION

# define BOOST_THROW_EXCEPTION(x) ::boost::exception_detail::throw_exception_(x,BOOST_THROW_EXCEPTION_CURRENT_FUNCTION,__FILE__,__LINE__)

it looks like it's not possible anymore.

<source>:9:70: error: no match for 'operator<<' (operand types are 'void' and 'boost::errinfo_errno' {aka 'boost::error_info<boost::errinfo_errno_, int>'})

Is this an oversight?

[pdimov]

I don't see why you think that would be possible. If you substitute the definition of BOOST_THROW_EXCEPTION you quote into the expression, the result is the exact same error.

[sdebionne]

My bad, I screw up with the parenthesis when reading the documentation, sorry. It would be nice to have though. Maybe something like this could be helpful

BOOST_THROW_EXCEPTION2(
    std::runtime_error("oupsy"),
    (boost::errinfo_errno(res))(boost::errinfo_file_name(filename))
)

or

boost::throw_exception(BOOST_EXCEPTION(std::runtime_error("oupsy")) << boost::errinfo_errno(res)) << boost::errinfo_file_name(filename));

or is there any other recommended way to achieve the same goal, that is, throw a boost exception with the function, file and line infos plus additional errinfos?

[pdimov]

The current way is

BOOST_THROW_EXCEPTION(boost::enable_error_info(std::runtime_error("oops")) << boost::errinfo_errno(res));

but this rarely occurs in practice because you typically throw your own exception type which already derives from boost::exception so the call to boost::enable_error_info is not necessary.

(In 1.73, there will be changes to throw_exception, but they don't affect this issue. See https://www.boost.org/doc/libs/develop/libs/throw_exception/doc/html/throw_exception.html.)

[sdebionne]

Thanks, Boost.ThrowException has everything I need in the end!