Confusing stuff with arrays
Deewiant
deewiant.doesnotlike.spam at gmail.com
Thu May 11 10:50:49 PDT 2006
What I was originally trying to do was make an array of type
char[][2][][char[]]. However, I needed to initialise it, which is a major pain
without array literals. A makeArray template essentially did the trick, but I
had to change the array to the type char[][][][char[]], since it seems that
arrays of static arrays don't work as they should, at least in this case.
The code (demonstrating a bunch of different issues, I think) below explains it
best. Am I just confused, or does it warrant a bug report or two?
(Aside from the array literals feature request, obviously <g>)
---
private import std.stdio;
// cheers to http://www.wikiservice.at/d/wiki.cgi?DocComments/Arrays
template makeArray(T){
T[] makeArray(T[] newArray...){
return newArray.dup;
}
}
void main() {
// this is fine
char[][2] foo = makeArray!(char[])("foo", "oof");
writefln(foo);
// adding a cast to the above makes it not work, strangely enough
// "e2ir: cannot cast from char[][] to char[][2]"
//char[][2] quuux = cast(char[][2])makeArray!(char[])("foo", "oof");
//writefln(quuux);
// "cannot assign to static array (__arrayArg2)[0]"
//char[2][] bar = makeArray!(char[2])("bar", "rab");
//writefln(bar);
// this is fine
char[][][] baz = makeArray!(char[][])(makeArray!(char[])("I want", "array
literals"), makeArray!(char[])("arrr", "ghhh"));
writefln(baz);
// "cannot assign to static array (__arrayArg7)[0]"
// "cannot assign to static array (__arrayArg7)[1]"
//char[][2][] zot = makeArray!(char[][2])(cast(char[][2])makeArray!(char[])("I
want", "array literals"), cast(char[][2])makeArray!(char[])("arrr", "ghhh"));
//writefln(zot);
// sort of works, but usage requires cast(char[][][]), defeating the whole point
char[][2][] qux =
cast(char[][2][])makeArray!(char[][])(makeArray!(char[])("Array", "literals
today"), makeArray!(char[])("pretty", "please?"));
// at runtime "Error: std.format formatArg"
// writefln(qux);
// outputs garbage
writefln(qux[0]);
// these work
writefln(cast(char[][][])qux);
writefln((cast(char[][][])qux)[0]);
// an interesting animal...
// at runtime "Error: array cast misalignment"
// why did this work in the above case?
// it seems that having only one array passed to the outer makeArray causes this
// is the error here, in the above, or just in all this messing about with evil
casting?
char[][2][] quux = cast(char[][2][])makeArray!(char[][])(makeArray!(char[])("I
want", "array literals"));
writefln(quux);
}
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