digitalmars.D - other array types than char in templates?
- dennis luehring (12/12) May 29 2007 what is the reason for allowing this
- BCS (4/22) May 29 2007 I'm with you on this.
- Reiner Pope (8/26) May 29 2007 I agree that it doesn't make sense, but you can do this hack:
- Daniel Keep (16/34) May 29 2007 I think it's because arguments to a template become part of its mangled
- Don Clugston (18/44) May 29 2007 That's not much of an issue. In fact, if you look at the ABI page,
what is the reason for allowing this template test(char[] bla) { ... } but not template test(int[] bla) { ... } or other bultin(own) types? ciao dennis
May 29 2007
dennis luehring wrote:what is the reason for allowing this template test(char[] bla) { .... } but not template test(int[] bla) { .... } or other bultin(own) types? ciao dennisI'm with you on this. see this: http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D&article_id=53939
May 29 2007
dennis luehring wrote:what is the reason for allowing this template test(char[] bla) { ... } but not template test(int[] bla) { ... } or other bultin(own) types? ciao dennisI agree that it doesn't make sense, but you can do this hack: template test(T...) { static assert(is(typeof(T[0]) == int[])); const int[] bla = T[0]; } -- Reiner
May 29 2007
dennis luehring wrote:what is the reason for allowing this template test(char[] bla) { .... } but not template test(int[] bla) { .... } or other bultin(own) types? ciao dennisI think it's because arguments to a template become part of its mangled name. Integers and floats are easy, as are actual strings, but to support arbitrary types, Walter would either need some kind of generic serialisation setup, or find a new way of mangling templates. At least, that's how I understand it :) -- Daniel -- int getRandomNumber() { return 4; // chosen by fair dice roll. // guaranteed to be random. } http://xkcd.com/ v2sw5+8Yhw5ln4+5pr6OFPma8u6+7Lw4Tm6+7l6+7D i28a2Xs3MSr2e4/6+7t4TNSMb6HTOp5en5g6RAHCP http://hackerkey.com/
May 29 2007
Daniel Keep wrote:dennis luehring wrote:Yes.what is the reason for allowing this template test(char[] bla) { .... } but not template test(int[] bla) { .... } or other bultin(own) types? ciao dennisI think it's because arguments to a template become part of its mangled name.Integers and floats are easy, as are actual strings, but to support arbitrary types, Walter would either need some kind of generic serialisation setup, or find a new way of mangling templates.That's not much of an issue. In fact, if you look at the ABI page, you'll see that the mangling scheme almost supports arbitrary types already. TemplateArg: T Type V Type Value S LName Any type which can be a type template parameter, and which has literals, could also be a value parameter. The problem is that the mangled names become too long, which makes bad things happen (eg, the obj file format imposes a maximum identifier length of ~ 3kB). There a few types (int[], short[] ubyte[]) which are essentially identical to the permitted dchar[], wchar[], char[], and could trivially be permitted. CTFE has drastically reduced the number of cases where it would be useful, though.
May 29 2007