Re: [boost] Re: Re: Boost 1.25.0 build problems?

From: Howard Hinnant (hinnant_at_[hidden])
Date: 2001-10-06 10:44:54

On Saturday, October 6, 2001, at 11:18  AM, David Abrahams wrote:

> <shudder!>That would mean that standard headers would always have to 
> include
> definitions for all types they use, because user-defined classes can 
> also
> have implicit conversions. I don't think you really mean that, do you?

I believe I do.  But perhaps your next example will convince me 
otherwise.

> #inlcude <iosfwd>
> struct sstream_pimpl
> {
>     sstream_pimpl();
>     ~sstream_pimpl();
>     operator std::basic_stringstream<char>&() const;
>     std::basic_stringstream<char>* m_data;
> };
>
> void g(std::basic_stringstream<char> const&);
>
> void f()
> {
>     sstream_pimpl x;
>     g(x);   // legal?
>     x << 1; // legal?
> }

g(x);  // Yes, legal.  I see no reason to have the complete definition 
of stringstream here.

x << 1;  // No, not legal.

Error   : illegal operand
HelloWorld.c line 24   x << 1; // legal?

-Howard