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From: serge@ucbvax.UUCP
Newsgroups: comp.lang.c,comp.lang.c++
Subject: ANSI C & C++ idea
Message-ID: <17516@ucbvax.BERKELEY.EDU>
Date: Tue, 24-Feb-87 20:31:27 EST
Article-I.D.: ucbvax.17516
Posted: Tue Feb 24 20:31:27 1987
Date-Received: Fri, 27-Feb-87 04:22:26 EST
Organization: University of California at Berkeley
Lines: 56
Keywords: ANSI, C, C++, idea
Xref: utgpu comp.lang.c:1148 comp.lang.c++:142

[]
    I would like to propose the following notation (valid only in function
argument declarations/definitions)

	void	f(return Type *t)

to mean that f() will only write the value pointed to by t, and not read it.

    That is,

	void	f(const Type *t)

would mean that f() only reads *t, and does not write it, while

	void	f(return Type *t)

would mean that f() only writes *t, and does not read it, and

	void	f(Type *t)

would mean that f() both reads and writes *t, e.g. t is a
value-result parameter.

    In addition, an argument declared as

	Type *t

could be passed to a function expecting a parameter of type

	const Type *t
or
	return Type *t
or
	Type	*t

    However, an argument declared as

	return Type *t

could only be passed to a function expecting a parameter of type

	return Type *t

and an argument declared as

	const	Type *t

could only be passed to a function expecting a parameter of type

	const	Type *t

    Comments?

						Serge
						serge@ucbvax.berkeley.edu
						...!ucbvax!serge