Re: Downloading Files in D
On Thursday, 11 September 2014 at 17:37:24 UTC, Nordlöw wrote: Ok, thanks. And I guess vibe.d can do this aswell without external dependencies, right? I'm also interested to know how this can be done with vibe.d...
Re: UFCS doesn't work in some cases
On Tuesday, 9 September 2014 at 18:46:31 UTC, ketmar via Digitalmars-d-learn wrote: UFCS is not working for nested functions. this is not a bug, it was designed this way. the same for 'with', i believe. Apparently it is a bug that UFCS doesn't work with 'with' statement. https://issues.dlang.org/show_bug.cgi?id=10349 there is rationale. see http://dlang.org/function.html, UFCS section. Must have missed it before, thanks.
UFCS doesn't work in some cases
Hi,
I don't know if this has been mentioned before, but I found two
strange cases where UFCS doesn't work.
Case # 1: When the functions for UFCS are defined inside main
scope
class Rect {
int x = 20;
int y = 20;
}
void main() {
import std.stdio : writeln;
int area(Rect rect) {
return rect.x * rect.y;
}
auto rect = new Rect;
rect.area.writeln; // Error: no property 'area' for type
'main.Rect'
}
Put that 'area' definition outside the main body and it works
fine.
Case # 2: When using UFCS in 'with' scope
class Rect {
int x = 20;
int y = 20;
}
int area(Rect rect) {
return rect.x * rect.y;
}
void main() {
import std.stdio : writeln;
auto rect = new Rect;
with(rect) {
area.writeln; // Error: function main.area (Rect rect) is not
callable using argument types ()
}
}
As far as I know, UFCS are designed to make it easy to extend the
class for specific applications, however, without the ability to
use UFCS for those cases, it limits its usefulness. Are these
oversights/bugs? Or is their any rationale behind the decision to
not implement UFCS for them?
Danyal
Re: Installing LDC on Windows
On Saturday, 6 September 2014 at 11:13:20 UTC, Russel Winder via Digitalmars-d-learn wrote: OK I installed LDC pre-built on MinGW for Windows on Windows and then Installed MinGW for Windows but when I run ldc2 it tells me libgcc_s_dw2-1.dll is missing. Is this problem soluble by any means other than destruction of Windows? You need to set PATH in environment variables to the directory where shared libaries of MinGW are present...
Re: Really nooB question - @property
On Sunday, 20 July 2014 at 16:35:52 UTC, Eric wrote:
There are a lot of discussions in the forums about how @property
should or could be implemented. But I can't seem to find
anything
that explains why or when I should use @property with the
current
compiler. Can anyone explain why and when I should use the
@property tag?
Consider the following struct:
struct Vector4 {
@property float x() { return vec[0]; }
.
.
@property void x(float _x) { vec[0] = _x }
.
.
private:
float[4] vec;
}
Here I like to use static array for storing components of vector
because I want to use special operations on arrays while taking
advantage of auto-vectorization if possible. In this case, it is
very convenient to use properties.
Re: DStyle: Braces on same line
On Sunday, 13 July 2014 at 16:10:31 UTC, Gary Willoughby wrote: Here is the 'official' style that is followed by most people including me. http://dlang.org/dstyle.html Unrelated to my original question. I already read that before asking.
Re: DStyle: Braces on same line
On Sunday, 13 July 2014 at 10:18:23 UTC, Joseph Rushton Wakeling via Digitalmars-d-learn wrote: However, I do think there's value in deliberately matching the code style of the standard library, as it extends the volume of public D code with a common style. So unless you have a strong personal preference, I'd go with that. I'm going with Andrei's style of preference on his talks ;)
DStyle: Braces on same line
Hi, I noticed that in Andrei's talks and his book, he used braces on the same line of delcaration, however Phobos and other D libraries I know use braces on their own line. Now I'm in a position where I need to take decision on coding style of my library and I get accustomed to use braces on same line but I'm worried if that would make my library less readable to other D users. Should I worry about it? Or is that's just a debatable style that won't really matter if it's persistent throughout library? Thanks
Re: struct template help
On Saturday, 12 July 2014 at 19:19:28 UTC, seany wrote:
For reasons further down in the software, I need to do this
with a pointer. How do I do it with a pointer, please?
I don't know what are you trying to achieve, but if that's what
you want, you can do:
void MYfunction()
{
auto strArr = [Hello, World!];
arc!(string, string[]) * a = new arc!(string, string[])(s,
strArr);
a.some_var = hello;
}
If you want to use a from outside the function you have to
declare it in the class and then initialize it in your function.
Re: struct template help
On Saturday, 12 July 2014 at 19:32:48 UTC, seany wrote:
do I have to initialize all variables of the struct? or may I
also use a this(){} in the struct and initialize only those
which are known at a given moment?
You can initialize in constructor this(), but you can't
initialize partial fields of struct when using pointer to struct.
There would be other trivial ways to do what you are trying to
do. Also, I never used any pointer to struct (which is of value
type) in my code .
Re: struct template help
On Saturday, 12 July 2014 at 19:42:13 UTC, Ali Çehreli wrote:
Actually, that works too but members must be initialized from
the beginning. The trailing ones are left with .init values:
struct S
{
int i;
string s;
}
void main()
{
auto s = new S(42);
static assert(is (typeof(s) == S*));
}
Ali
Ah, right. I still has C++ background in my veins I guess :)
Re: DStyle: Braces on same line
On Saturday, 12 July 2014 at 19:35:11 UTC, anonymous wrote: There is another stylistic choice which I do find confusing: capitalized identifiers for non-types, e.g. variables and functions. Please don't do that. Agreed about variables and functions. However I personally prefer to use PascalCased identifiers in enum unlike what is preached in Dstyle page.
Using two flags in conditonal compilation (version)
Hi, In the development of my library, I'm in a position where I
need to add support for multiple compilers. For instance,
supporting both the assembly of LDC/DMD and GDC. I want to do
something like:
version(DigitalMars LDC)
{
}
However, it doesn't compile which forces me to rewrote the same
code for both DigitalMars and LDC
version(DigitalMars)
{
}
version(LDC)
{
}
Is there a way to check both versions at the same time? (I can't
seem to find the solution through google, sorry)
Thanks,
Danyal Zia
Converting from C const(dchar*) to dstring
Hi, I like to print the strings from a C function that returns const(dchar*), but I can't make the conversion to dstring. I can convert vice versa by: dstring text = Hello; const(dchar)* str = toUTFz!(const(dchar)*)(text); // passing it to C function prints Hello However, I don't have the idea how can I go the other way. I tried several methods such as using to!dstring, toUTF32 etc which compiles successfully however printing them gives address of them instead of text. Thanks, Danyal Zia
Re: Converting from C const(dchar*) to dstring
On Tuesday, 24 June 2014 at 17:59:41 UTC, Steven Schveighoffer wrote: const(dchar *)x = ...; // assuming 0 terminated dstring text = x[0..x.strlen].idup; -Steve const(dchar)* x = Hello\0; dstring text = x[0..x.strlen].idup; writeln(text); Error: no property 'strlen' for type 'const(dchar)*'
Re: Converting from C const(dchar*) to dstring
On Tuesday, 24 June 2014 at 18:34:31 UTC, Chris Cain wrote:
You can do what he said, but you'll have to write your own
strlen function:
something like:
size_t strlen(in dchar* s) pure @system nothrow
{
size_t pos = 0;
dchar term = '\0';
while(s[pos] != term)
++pos;
return pos;
}
const(dchar)* ds = hello\0;
dstring text = ds[0..strlen(ds)].idup;
writeln(text);
works
It works indeed, thanks a lot! Any chance of making it into std
phobos?
