if(p)

[Mike Woods]

Followup-To:
Xpath: warwick ubu

In article <1671 at brl-tgr.ARPA> ART at ACC.ARPA (Art Berggreen) writes:
>From an abstract language viewpoint, an "if" statement conditionally
>executes a block of statements based on whether the control statement
>evaluates to a condition of *TRUE*.  Pointers by themself do not
>have attributes of TRUE vs FALSE.  Thus, "if(pointer)" makes less semantic
>sense than "if(pointer == SOME_VALID_POINTER_VALUE)".  What to test against
>has been discussed in previous messages.

But from an abstract viewpoint, pointers can be considered to have
two states: valid or invalid. Therefore, "if (pointer)" can be read
as "if (pointer is valid)". At least this is how I look upon such
things (though the first time I saw it my mind stopped functioning
for five minutes (the legacy of Fortran!)).

Mike (I don't think logically; I think C) Woods.
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