Re: [boost] [system] Would it be possible to trial a breaking change to Boost.System and see what happens?

-----Original Message----- From: Boost [mailto:boost-bounces@lists.boost.org] On Behalf Of Vinnie Falco via Boost Sent: 19 January 2018 17:16 To: boost@lists.boost.org Cc: Vinnie Falco Subject: Re: [boost] [system] Would it be possible to trial a breaking change to Boost.System and see what happens?

On Sat, Jan 13, 2018 at 8:05 PM, Christopher Kohlhoff via Boost wrote:

...

The error_code class itself deliberately does *not* imbue zero values with the meaning 'success' and non-zero values with the meaning 'failure'. An error_code simply represents an integer and a category, where the category identifies the source of a particular integer value. The specification of the error_code class carefully avoids making any judgement as to whether a particular value represents success or failure. The construct:

if (ec) ...

does not, in and of itself, mean 'if an error ...'. Instead, operator bool is specified to behave as the ints do, and the above construct should simply be read as 'if non-zero ...'.

That might have been the original design intention, but that ship sailed a long time ago. It is well established that users are habituated to think of the bool conversion as meaning success or failure.

Nobody wants to write

if(ec == my_condition::success)

When then can instead write

if(! ec)

But who wants to *read* if(! ec) when it is 'ambuguous'? (and the ! can easily be missed at a glance.) Boost prefers clarity to curtness. if(! ec) is a bad habit - just stop it! Now! Paul PS but don't mess with existing code that works OK.