🚀 go-pugleaf

In article <199604020902.LAA06787@bredex.bredex.de>,
Nico Josuttis <nico@bredex.de> writes:
>
>Following the standard, all find() member functions for string
>return string::size_type and may have the value string::npos,
>which is (size_type)-1.

   ... example elided...

>    This seems unhandy und thus dangerous as people might
>    try to make the code simpler:
>    For example:
>	int pos
>	pos = s.find('x');
>	if (pos == string::npos)
>    or even
>	if (pos == -1)
>
>    The problem is that the test with operator== fails if
>	sizeof(size_type) != sizeof(int)
>    because unfortunately then
>	(size_type)-1 is not -1
>    This is due to the conversion to unsigned.
>
>    Am I missing something or are these problems known?
>    Why wasn't taken a simpler and safer interface?

Obviously these problems are known, because that is why the type 
string::size_type and the constant string::npos were defined. This
is the safe interface, and I don't think it can be any simpler.
In fact I feel it is easier to read than "if( pos == -1 )" and
hides the implementation of the string. Is it really a problem to
type 14 extra characters, expecially when the result is code
which is more readable, easier to maintain, and *works*?
Basically, if you don't write to the interface then you cannot
expect your code to work in all cases. That is the point of an 
interface, after all.

>
> 2.) I wonder what "npos" means.
>     Could somebody tell me?
>

How about "no position"?



Cheers,
        Nat.
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| Name:   Nat Pryce MEng ACGI            O- | Mail:  Department of Computing,|
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