🚀 go-pugleaf

In article 95Oct26140846@avs.cs.rpi.edu, vandevod@cs.rpi.edu (David Vandevoorde
) writes:
>
>>>>>> "SC" == Steve Clamage <clamage@eng.sun.com> writes:
>[...]
>SC> You can use the enum hack, but it isn't necessary. You can now (if
>SC> your local compiler supports the change) declare a static member of
>SC> any integral type as a manifest constant:
>[...]
>
>Would you happen to know why it must be an ``integral type''?
>I imagine uses for floating-point constants...

I believe it is because integral constant-expressions are a special item
in the language.  A floating-point constant-expression may consist only
of floating-point literals. For example, at file scope:

	const int two = 2; // 'two' is a constant-expression
	int k = two; // OK

	const double pi = 3.1415926535798;
	double x = pi; // error, 'pi' is not a constant-expression

So it seems to me that being able to write
	struct T { static const double e = 2.7182818285; };
doesn't give you any added capability or convenience compared to
	struct T { static const double e; };
because you must still provide a definition someplace.

We might someday revisit the restrictions on floating-point constants,
but it seems to me the rules are at least consistent.
---
Steve Clamage, stephen.clamage@eng.sun.com
---
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