Expressions in initializers

[Chris Torek]

In article <17294 at crdgw1.crd.ge.com> volpe at camelback.crd.ge.com
(Christopher R Volpe) writes:
>"The square root of two" can be evaluated at compile time, but "sqrt(2.0)"
>is an invocation of a function. How is the compiler supposed to know
>what sqrt is? I could have in another file:
>
>double sqrt(double x)
>{
>  return x - 1.0;
>}

Not in ANSI C (at least, not if you `#include <math.h>'; I am not sure
about the case where you do not include the standard header).  Compilers
can of course define their own languages and allow

	static double root2 = sqrt(2.0);

but someone writing ANSI C should assume neither this nor that writing

	double sqrt(double x) { return x - 1.0; }

will work.
-- 
In-Real-Life: Chris Torek, Lawrence Berkeley Lab EE div (+1 415 486 5427)
Berkeley, CA		Domain:	torek at ee.lbl.gov