Re: [boost] Operating System API Error Reporting Guidelines

From: Peter Dimov (pdimov_at_[hidden])
Date: 2006-02-19 11:38:36

Beman Dawes wrote:
> "David Abrahams" <dave_at_[hidden]> wrote in message
> news:u1wy1wipv.fsf_at_boost-consulting.com...

>> Does it worry you that this will potentially expose an implementation
>> detail of the functions (i.e. that they use a system call) which may
>> even differ from platform to platform, making code nonportable?
>
> Some libraries (Boost.Filesystem for example) really shouldn't try to
> hide the fact that there is an operating system underneath.

What worries me is that with a single blessed system_error_code_type, the 
Filesystem approach (always implement directly on top of the OS) is imposed 
upon other libraries that may have other options. A threading library, for 
example, may sit on top of a pthread_* layer instead of talking directly to 
the OS; this means that it will get errno error codes back and not 
GetLastError.

Even Boost.Filesystem is possible to implement on top on Microsoft's 
POSIX-like API and never talk to the OS directly.