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From: bs@alice.UucP (Bjarne Stroustrup)
Newsgroups: net.lang.c
Subject: "structure constants" C++
Message-ID: <6022@alice.uUCp>
Date: Fri, 5-Sep-86 21:35:33 EDT
Article-I.D.: alice.6022
Posted: Fri Sep  5 21:35:33 1986
Date-Received: Sat, 6-Sep-86 20:24:37 EDT
Organization: Bell Labs, Murray Hill
Lines: 34

Karl W. Z. Heuer writes:

> BMS-AT!stuart writes:
> >I would like to see "structure constants" which would allow assignment to
> >aggregate types.
> >       complex z;
> >       z = { a+1, exp(b) };
> >       foo( (complex) { a, b } );
> 
> The problem, as your last example points out, is that the notation "{...}"
> doesn't distinguish between different structure types.  I suppose the cast
> notation is workable, but kinda ugly.

Or in C++:

#include <complex.h>

void foo(complex);

void f() {
	double a,b;
	complex z;
	z = complex(a+1,exp(b));
	foo( complex(a,b) );
}

> >Of course any of these could be coded by assigning each member in turn.
> 
> No, the last example requires assigning each member to a temporary, and then
> passing that temporary as an argument.

However, a clever compiler might use the calling stack as the temporary, but that
is tricky (C++ doesn't attempt that feat).