The D Programming Language
in [C++]
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From: kwikius on 28 Nov 2006 11:09 Walter Bright wrote: > kwikius wrote: > > A 2D 3D point or vector would be much more useful to me than complex > > numbers and of course I would want both vectors and complex numbers to > > work with my types, which I will bet the D version wont do. > > Why would you assume it won't? Do int's not work with your types? Well to work with my quantity types you need a signature of template <typename T1, typename T2> typeof(T1() / T2()) operator / (complex<T1> const &, complex<T2> const&) etc (If that is the signature of the D complex I apologise) for example typedef complex<quan::resistance::kR> impedance; impedance z = complex<quan::voltage::mV>() / complex<quan::current::mA>(1); Recently also I have discovered the power of 'static types. for example: static_double<0> operator *(double const & , static_double<0>) { return static_double<0>(); } which of course is easily resolved to a no-op by the compiler In this case my complex would have two params: template<typename Real, typename Imag> struct complex; for an imaginary type : typedef static_<double,0> zero; typedef complex<zero,double> imag; Although an imaginary type would be superior. For both C++ and D the real battle is comprehensive standard libraries though IMO. regards Andy Little -- [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ]
From: Nemanja Trifunovic on 28 Nov 2006 11:09 > > size_type find (charT c, size_type pos = 0) const; > > What if c isn't ASCII? > > Consider this snippet from the Standard: > > string s1("abc"); > string::iterator i = s1.begin(); > string s2 = s1; > *i = 'a'; > > How is that supposed to work, if 'a' is not ASCII? But what woud you expect? The user simply must take the string encoding into consideration when doing string operations like that. If s1 contains a string in some multibyte encoding the user must be aware of it. This is not specific to utf-8. -- [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ]
From: Walter Bright on 28 Nov 2006 14:13 kwikius wrote: > Walter Bright wrote: >> kwikius wrote: >>> A 2D 3D point or vector would be much more useful to me than complex >>> numbers and of course I would want both vectors and complex numbers to >>> work with my types, which I will bet the D version wont do. >> Why would you assume it won't? Do int's not work with your types? > > Well to work with my quantity types you need a signature of So you're doing dimensional analysis with C++ templates? Yes, you can do that with D, and there's at least one person doing so (Oskar Linde). -- [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ]
From: David Abrahams on 28 Nov 2006 14:27 Walter Bright <walter(a)digitalmars-nospamm.com> writes: > David Abrahams wrote: >> But then, I've never insisted on the ability to redefine >> syntax and tokens, and I don't even believe it's necessary in order to >> achieve the kind of flexibility and power I'm describing. > > How would you do it, then? Several features could come together to do the job: excellent first-class constant folding and first-class code block/expression types come to mind. Some Haskell-style composed operators might help, but probably aren't strictly necessary. BTW, string literals would be a builtin feature, there's no question about *that*. -- Dave Abrahams Boost Consulting www.boost-consulting.com [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ]
From: Walter Bright on 28 Nov 2006 14:24
Nemanja Trifunovic wrote: > But what woud you expect? The user simply must take the string encoding > into consideration when doing string operations like that. If s1 > contains a string in some multibyte encoding the user must be aware of > it. This is not specific to utf-8. If it supported utf-8, I would expect things like encoding and decoding of utf-8 to work. std::string right now offers nothing for the utf-8 user. -- [ See http://www.gotw.ca/resources/clcm.htm for info about ] [ comp.lang.c++.moderated. First time posters: Do this! ] |