Re: [Algorithms] programmer productivity versus runtime performance - "compiler firewall"

[Peter D. <pd...@mm...>]

From: "Robert Dibley" <RD...@ac...>

> Why can't the size be sorted out at link time ?  I mean if the class will
> have a size which isn't known when you link, then obviously it has to be
> allocated at run-time, but that applies to anything.  However it seems to
me
> that there is no reason why an object file / library has to know the
> data-sizes of the things it is working with ... it should be possible for
a
> linker to sort those things out just like it sorts out hundreds of others.

Historical reasons. The original C++ had to work with C-style linkers. The
current language seems to require smarter linking, however (exported
templates) so I don't know. It might be possible to do this at link time. Or
it might not. C++ is a terribly complex language.

It's easier (from a language designer/compiler writer point of view) to
optimize small dynamic memory allocations to be nearly as fast as stack
allocations and use 'new impl.'

--
Peter Dimov
Multi Media Ltd.