maart@cs.vu.nl (Maarten Litmaath) (03/03/89)
karl@haddock.ima.isc.com (Karl Heuer) writes:
\After `typedef char *string',
\`string const x' means `char * const x' rather than `char const * x'.
Of course. But I was talking of `const string x'; in my opinion this should
mean `const char *x'. ADO's example `const string const x' should translate to
`const char * const x'. I guess the problem is the equivalence of `const char'
and `char const', which - generalized - leads to `const string' ==
`string const'. This equivalence is dubious, or?
BTW, how about letting `const double sin(double)' mean
"sin() is a `true' function"? (`true': same args -> same result [i.e. no
side-effects])
--
"Those who do not understand Henry |Maarten Litmaath @ VU Amsterdam:
Spencer are condemned to reinvent DOS." |maart@cs.vu.nl, mcvax!botter!maartkarl@haddock.ima.isc.com (Karl Heuer) (03/04/89)
In article <2117@solo11.cs.vu.nl> maart@cs.vu.nl (Maarten Litmaath) writes: >karl@haddock.ima.isc.com (Karl Heuer) writes: >>After `typedef char *string', >>`string const x' means `char * const x' rather than `char const * x'. > >Of course. But I was talking of `const string x'; in my opinion this should >mean `const char *x'. Having (const int)==(int const) but (const string)!=(string const) would somewhat defeat the purpose of typedefs as an abstraction mechanism. The user shouldn't have to know that "string" is a pointer type. Actually, I think that allowing a type qualifier before the type name is as dubious as allowing the storage class to be after it (which is now obsolescent). In my view, `static int const x' is the correct way to write that declaration. Writing `const' before `int' is misleading; it suggests that `const' behaves like a storage class. (This entire paragraph is the opinion of the author and is not intended to spark a new programming-style war. I will probably not bother to respond if such a war erupts anyway.) >BTW, how about letting `const double sin(double)' mean [sin() is pure]? I already noted this possibility in <11819@haddock.ima.isc.com>. I have since been informed that the latest version of gcc does in fact use `const' to mark pure functions, and `volatile' to mark nonreturning functions. As I said in the aforementioned article, though: |It remains unclear whether this would be any less of a mistake than the |overloading of `static' and `break'. Karl W. Z. Heuer (ima!haddock!karl or karl@haddock.isc.com), The Walking Lint