Re: CTFE and structs question
g wrote:
At what point structs are supported in CTFE.
Cause this fails in dmd 2.036:
import std.metastrings;
pragma(msg,toStringNow!(A.init.a));
struct A{
uint a;
}
with this message (note that the end seems truncated):
g...@g-desktop:~/Documentos/NCHESS$ dmd oh
oh.d(3): Error: no property 'a' for type 'A'
toStringNow!(__error)
g...@g-desktop:~/Documentos/NCHESS$
also, ¿Is there any way to generate structs with ctfe or it is obligatory to
use templates?
You can create them without templates. std.metastrings was created
before CTFE existed, it's rather outdated. It's intended for use with
template metaprogramming, not for use with CTFE.
You can do stuff like:
struct Foo {
int x;
}
enum Foo b = Foo(56);
Re: Using ANSI codes
Daniel Keep wrote: http://github.com/DanielKeep/gb/blob/master/src/gb/io/Ansi.d I noticed this comment: /* We only need to override write for Windows, since it's the only OS * that doesn't understand ANSI. The ONE spot where 9x is better than * NT... */ This is incorrect - ANSI.SYS is still included in modern Windows versions, at least up to Vista; the only difference is whether it's switched on by default. But libraries such as yours at least mean that the codes will work regardless of whether the end user has ANSI.SYS switched on. But disp.h, which I've already mentioned, also has the same advantage. So unless the OP is porting an app that already uses ANSI codes, or writing a terminal emulator or something Stewart.
CTFE and structs question
At what point structs are supported in CTFE.
Cause this fails in dmd 2.036:
import std.metastrings;
pragma(msg,toStringNow!(A.init.a));
struct A{
uint a;
}
with this message (note that the end seems truncated):
g...@g-desktop:~/Documentos/NCHESS$ dmd oh
oh.d(3): Error: no property 'a' for type 'A'
toStringNow!(__error)
g...@g-desktop:~/Documentos/NCHESS$
also, ¿Is there any way to generate structs with ctfe or it is obligatory to
use templates?
Re: 2 File IO Questions (Phobos)
Frank Benoit Wrote: > Zane schrieb: > > Doh! I still need help with number 2, but for number 1, all I needed > > was to use 'writeString' instead of 'write'. Like I said, still > > getting used to Phobos. Like I said, I still need help on the > > destructor question (#2). > > > > Thanks, Zane > > desctructors are called in not defined order. The GC puts your class > instance 'sw' and the File instance 'sw.file' onto the list for > destruction. So the 'sw.file' might be destructed before 'sw' is. > Deferencing sw.file from withing sw.~this then fails. > > A general rule: in a dtor, never dereference member variables. > > You have to rely on the File dtor, to close himself if still open. I understand, thanks very much!
Re: 2 File IO Questions (Phobos)
Zane schrieb: > Doh! I still need help with number 2, but for number 1, all I needed > was to use 'writeString' instead of 'write'. Like I said, still > getting used to Phobos. Like I said, I still need help on the > destructor question (#2). > > Thanks, Zane desctructors are called in not defined order. The GC puts your class instance 'sw' and the File instance 'sw.file' onto the list for destruction. So the 'sw.file' might be destructed before 'sw' is. Deferencing sw.file from withing sw.~this then fails. A general rule: in a dtor, never dereference member variables. You have to rely on the File dtor, to close himself if still open.
Re: 2 File IO Questions (Phobos)
Zane Wrote:
> Hello all,
>
> I have been looking at Phobos lately, and currently I am having some trouble
> understanding what is going on with the following 2 trivial examples. First
> of all, I am using dmd v1.050.
>
> This one prints "[‼ This is some stuff!]". Where do the 4 prepended
> bytes come from?
> (1) >
>
> import std.stream;
> import std.stdio;
>
> int main()
> {
> char[] stuff = "This is some stuff!";
>
> File f = new File("stuff.txt", FileMode.Out | FileMode.In);
> f.write(stuff);
> f.seekSet(0);
> stuff = f.readLine();
> writef("[%s]", stuff);
> f.close;
>
> return 0;
> }
>
>
> This one I wanted to have a class open a file upon initialization of an
> instance, and close a file when the destructor is called. I get an "Error:
> Access Violation" unless I comment out the file.close line. Why? (of course
> this example also has the same problem as the first example, but I kept the
> first one simpler to narrow down things)
> (2) >
>
> import std.stream;
>
> public class StuffWriter
> {
> File file;
>
> this(char[] filename)
> {
> file = new File(filename, FileMode.Out);
> }
>
> ~this()
> {
> file.close; //this causes an access violation???
> }
>
> public void write(char[] stuff)
> {
> file.write(stuff);
> }
> }
>
> int main()
> {
> StuffWriter sw = new StuffWriter("stuff.txt");
> sw.write("This is some stuff!");
>
> return 0;
> }
>
>
> Thanks!
> Zane
Doh! I still need help with number 2, but for number 1, all I needed was to use
'writeString' instead of 'write'. Like I said, still getting used to Phobos.
Like I said, I still need help on the destructor question (#2).
Thanks,
Zane
2 File IO Questions (Phobos)
Hello all,
I have been looking at Phobos lately, and currently I am having some trouble
understanding what is going on with the following 2 trivial examples. First of
all, I am using dmd v1.050.
This one prints "[‼ This is some stuff!]". Where do the 4 prepended
bytes come from?
(1) >
import std.stream;
import std.stdio;
int main()
{
char[] stuff = "This is some stuff!";
File f = new File("stuff.txt", FileMode.Out | FileMode.In);
f.write(stuff);
f.seekSet(0);
stuff = f.readLine();
writef("[%s]", stuff);
f.close;
return 0;
}
This one I wanted to have a class open a file upon initialization of an
instance, and close a file when the destructor is called. I get an "Error:
Access Violation" unless I comment out the file.close line. Why? (of course
this example also has the same problem as the first example, but I kept the
first one simpler to narrow down things)
(2) >
import std.stream;
public class StuffWriter
{
File file;
this(char[] filename)
{
file = new File(filename, FileMode.Out);
}
~this()
{
file.close; //this causes an access violation???
}
public void write(char[] stuff)
{
file.write(stuff);
}
}
int main()
{
StuffWriter sw = new StuffWriter("stuff.txt");
sw.write("This is some stuff!");
return 0;
}
Thanks!
Zane
