Re: basic_string ctor

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Duane Hebert wrote: 
"Carl Daniel [VC++ MVP]" <cpdaniel_remove_this_and_nospam@xxxxxxxxxxxxxxx> wrote in message
news:eUe10xwWFHA.2768@xxxxxxxxxxxxxxxxxxxxxxx

John wrote:

Hi,

Is it legal C++ (by which I mean according to the standard spec) to
pass a null into a basic_string ctor?  Or, more precisely, is it
legal C++ to pass a null pointer into a basic_string parameter on a
method?


No, it's not.  The committee was worried about the cost of the extra if() in
the constructor being too high (misplaced premature optimization, IMO).



In my opinion the cost of the extra if() would have been well worth
it.  One of the problems with the string.h functions was the need to
check everything (if(ptr)(if strlen(prt)) //do something with ptr)

Having functions that take std::string and give expected results
with null would have been great.  I've heard from people involved
with the standard that this may be changed.

What behaviour should we have for passing null? An exception thrown? Certainly I don't particularly like the idea of treating null identically to "", since they aren't the same thing.

Tom
.

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