Re: Flexible Strings (was Equality operator...)

[dewar@merv.cs.nyu.edu (Robert Dewar)]

<<But the C standard firmly says that ``The free function causes the space
pointed to by ptr to be deallocated, that is, made available for further
allocation'' (ISO 9899:1990 7.10.3.2 The free function). This pretty much
constitutes a requirement that the C implementation actually deallocate
when free is called, which carries more weight than a mere observation
about what all existing implementations do.>>

Let me give a possible implementation of the C standard. Suppose we are
on a machine with huge address space, and lots of virtual memory. We
assume for example a 256-bit virtual address space.

Now our C implementation works this way, malloc always returns the
next sequentially available location. Free works by simply removing
the relevant pages from the page table.

This is a perfectly defensible and usable implementation of C. Would
it violate the standard? Of course not!