Array by value

[Martin Minow]

Arnold Robbins suggests adding the ` operator to C to mean
"array by value" as in:

    int a[10]; b[10];
    ...
	`a = `b;	/* I may have misrembmered the syntax */

There are several problems with this.  First, all C expressions
return a value, so I should be able to write statements such
as

	if ((`a = `b) != 0)

which is going to cause great pains for compiler writers.

The other problem is that this suggestion rejects one of the
primary C design philosophies -- that of making "easy things
easy and hard things hard".  Most compiler writers will
generate something like "`a = `b":

	_bcopy(&a[0], &b[0], sizeof a);

A suitably written _bcopy will run at memory speeds for all non-trivial
cases.

I am willing to bet that all the reasonable "array by value"
operations could be implemented just as efficiently by
a macro preprocessor.

I should also note that Andrew's other suggested operator, '$'
is valid in identifiers in Vax-11C, Decus C, and probably
a few other PDP-11 compilers running on Dec machines.  ('$' is
necessary to access system-wide variables on Dec operating
systems.)

Martin Minow
decvax!minow