Re: reducing needless normal_iterator usage in vector

[Phil Edwards <phil at jaj dot com>]

On Tue, Jul 02, 2002 at 07:16:41PM +0200, Theodore Papadopoulo wrote:
> phil@jaj.com said:
> > Replacing simple expressions like "begin() + n" with "_M_start + n"
> > skips the normal_iterator ctor and the normal_iterator's overloaded
> > ops, and gets right to the pointer arithmetic that we eventually do
> > anyway. 
> 
> I believe the only reason is for abstraction. If someone, one day, 
> redefine normal_iterator to be something else than a pointer, he will 
> not have to re-examinate all the vector code but just implement a 
> normal_iterator class that provides the relevant operations.

That would not affect the internals at all.  We must always use a simple
pointer in the underlying operations, just because we're required to use
contiguous storage in a vector.  The external iterator implementation can
be normal_iterator or anything more complicated; that has nothing to do
with it.  I'm saying that we don't need to use any of that for the internals.


Phil

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