Comment #0 by matti.niemenmaa+dbugzilla — 2009-06-13T06:50:26Z
The below code compiles, but shouldn't: array operations can't be used as initializers according to the spec, they need a slice as the lvalue.
void main() {
auto x = [2,3,4];
auto y = [1,1,1];
auto z = x[] - y[];
assert (z == [1,2,3]);
}
The assertion fails: z becomes a dynamic array with length 0 and an invalid pointer.
A similarly incorrect array results with most other operators. Using +, however, gives the following strange diagnostic:
foo.d(5): Error: Array operation x[] + y[] not implemented
This makes no sense, since x[] + y[] itself is perfectly fine as well as implemented.
Replacing 'auto z' with 'int[3] z' makes all cases succeed, but that contradicts the spec. IMHO there's no reason why using array operations as initializers should be invalid but that's what the spec currently says; added the 'spec' keyword to this in the hopes that this is legalized.
Comment #1 by k-foley — 2009-07-15T06:51:21Z
I have recently discovered some bugs that are related to this
---
import std.stdio;
int main()
{
int[] a = [1, 2, 3][];
int[] b = a[] + 4;
writeln("-> ", b); // -> 1 2 3 0 1935766371 1768515939 1764585331
int[] c;
c[] = a[] + 4;
writeln("-> ", c); // ->
c = [1, 1, 1][];
c[] = a[] + 4;
writeln("-> ", c); // -> 5 6 7
c = [0][];
c[] = a[] + 4;
writeln("-> ", c); // -> 5
c = a[] + 4;
writeln("-> ", c); // -> 1 2 3 0 1935766371 1768515939 1764585331
int[3] d = a[] + 4; // this is ok
writeln("-> ", d); // -> 5 6 7
int[3] e = [1, 2, 3];
int[3] f = [5, 6, 7];
//writeln( "-> ", e[] + f[] ); // Compile Error -- Error: Array operation e[] + f[] not implemented
// yet, this works:
writeln( "-> ", e.dup[] += f[] ); // -> 6 8 10
return 0;
}