Re: Boost 1.25.0 build problems?

From: williamkempf_at_[hidden]
Date: 2001-10-08 09:19:53

--- In boost_at_y..., "Peter Dimov" <pdimov_at_m...> wrote:
> From: <williamkempf_at_h...>
> > --- In boost_at_y..., "David Abrahams" <david.abrahams_at_r...> wrote:
> > > Arguably. Is it better to break loudly when the user does 
something
> > > nonportable, or to understand their intention and "just work"?
> >
> > It can be argued, though, that I didn't do anything "nonportable".
> > I've included all the relevant headers according to the 
requirements
> > of the standard with one viewpoint on this.
> 
> No, I think that the standard is pretty clear here. You are 
constructing a
> temporary of type std::string without including <string> first.
> 
> > Technically I haven't
> > since I inderectly used std::string by calling the std::exception
> > type's constructor, but then we come back to wondering if the 
design
> > of the std::exception types are broken.  I *truly* don't think 
it's
> > unreasonable to expect that I shouldn't have to explicitly include
> > <string> when I construct a std::exception type if I never use
> > std::string myself.  I don't really care if <exception> includes
> > <string> or not, so long as I don't have to do so myself when I 
never
> > use std::string.  There's two ways to do this right in my mind:
> > either <exception> must include <string> or all std::exception 
types
> > need to have overloaded constructors that take const char* 
parameters.
> 
> Perhaps the standard needs to be fixed (there are other reasons for 
this -
> the std::string constructor may throw); the way to do this is via a 
defect
> report or an extension proposal. But currently your code does not 
conform.
> 
> A question, though: what are you trying to gain by not including 
<string>?
> Your code will work only if <stdexcept> does include it anyway, so 
you're
> not saving anything.
> 
> In fact STLPort is trying to save you from including <string> if 
you don't
> need it.

I don't need it.  I didn't use it.  That's the whole point.  The fact 
that the exceptions demand that you use std::string to construct them 
is simply wrong.  Either one or the other cases would be acceptable, 
but what happens here is not.

1)  I don't need <string> to construct an exception with a const 
char* parameter.
2)  <string> is included by <exception> because I do need it for 
construction via a const char*.

The latter would be acceptable, though it causes extra dependency 
overhead so the former would be preferred.  This is all a technical 
problem with the current definition in the standard and so STLPort is 
fully conforming and I do have to include <string> myself.  However, 
I contend this is also a QoI issue because STLPort didn't have to 
take this route in their implementation even if the standard allows 
it.

Bottom line is that I don't use std::basic_string anywhere in the 
code and should not have to include <string> because there's a 
dependency on it in <exception>.  Either the dependency shouldn't be 
there, or <exception> should include <string> itself.

Bill Kempf