(ref.doc)horstman 140395

From: [email protected] (Cay Horstmann)
Newsgroups: comp.std.c++
Subject: Re: STL iterator model
Date: 14 Mar 1995 15:32:48 GMT

John Max Skaller ([email protected]) wrote:

: 	If anything, the conversion

: 	operator bool()const

: would make more sense in cases like

: 	while(it) { ..}

Wasn't it some C++ programmer who said that those who forget their 
history are condemned to repeat it? 

There is a reason why one converts to void* to test for truth values.
Of course, a conversion to bool would be the more logical approach, but it
would make a lot of expressions compile with nonsensical meanings. Consider
	container<T>::iterator it1, it2, it3;
	if (it1 == it2 + it3) ...
for iterators or
	cin << 10
for streams. This is because bool->int remains an implicit conversion.