On Thursday, 16 March 2017 at 17:20:45 UTC, H. S. Teoh wrote:
I'm not convinced casting static array to immutable is OK.
Check this out:
import std.stdio;
char[32] func() {
char[32] staticArr = "A123456789abcdefB123456789abcdef";
return staticArr; // OK, by-value return
}
string gunk() {
string x = func(); // implicit conversion char[32] ->
string
writeln(x.ptr);
writeln(x); // prints "A123456789abcdefB123456789abcdef"
return x;
}
void main() {
auto s = gunk();
writeln(s.ptr); // prints same address as in gunk()
writeln(s); // prints corrupted string
}
Run this code and you'll see that s.ptr has the same address as
x.ptr, and that x.ptr is the address of a local variable. This
is blatantly wrong.
Filed a new issue for this:
https://issues.dlang.org/show_bug.cgi?id=17261
Exactly, if there was a variable of type char[32] on the right
hand side of
string x = func();
instead of the call of func, then the compiler would complain. So
this is a bug.
