Re: D vs perl6
On Monday, 19 November 2018 at 06:46:55 UTC, dangbinghoo wrote: So, can you experts give a more comprehensive compare with perl6 and D? Sure! 1). You can actually read and understand D code.
Re: How do I install a library?
On Friday, 9 November 2018 at 00:18:28 UTC, H. S. Teoh wrote: It's not true that you're stuck with dub. And I'm not among the people who think dub is the way to go (though it's true that that's a minority opinion around here). Where I have a choice, my own D projects do not use dub. Me neither, I think it's a lot of work for little benefit and doesn't seem all that easy to use either. I rather use rdmd using -I flags.
Re: Which Docker to use?
On Wednesday, 17 October 2018 at 03:37:21 UTC, Ky-Anh Huynh wrote: Hi, I need to build some static binaries with LDC. I also need to execute builds on both platform 32-bit and 64-bit. From Docker Hub there are two image groups: * language/ldc (last update 5 months ago) * dlang2/ldc-ubuntu (updated recently) Which one do you suggest? Thanks a lot. To be honest, you don't need docker for this. You can just download LDC in a self-contained folder and use it as is. https://github.com/ldc-developers/ldc/releases That's what I do on Linux.
Re: Converting a character to upper case in string
On Friday, 21 September 2018 at 12:15:52 UTC, NX wrote:
How can I properly convert a character, say, first one to upper
case in a unicode correct manner?
In which code level I should be working on? Grapheme? Or maybe
code point is sufficient?
There are few phobos functions like asCapitalized() none of
which are what I want.
Use `asCapitalized` to capitalize the first letter or use
something like this:
import std.conv;
import std.range;
import std.stdio;
import std.uni;
void main(string[] args)
{
string input = "noe\u0308l";
int index= 2;
auto graphemes= input.byGrapheme.array;
string upperCased = [graphemes[index]].byCodePoint.text.toUpper;
graphemes[index] = upperCased.decodeGrapheme;
string output= graphemes.byCodePoint.text;
writeln(output);
}
Why do some attributes have an @ symbol and others don't?
Why do some attributes have an @ symbol and others don't? I thought it might be because some are used as keywords for other things but then 'pure' doesn't follow that rule. Any ideas? Is it just a legacy thing?
Re: Is there a way to anonymously execute some sh script contents?
On Wednesday, 1 August 2018 at 14:58:56 UTC, Ky-Anh Huynh wrote: This works well with user interaction. However I don't really like the idea of using temporary files. Is there any better way? Maybe take a look at: https://dlang.org/library/std/process/pipe_shell.html
Re: Check whether a range is empty
On Friday, 13 July 2018 at 18:37:35 UTC, vino.B wrote:
Hi All,
How do i check whether a range is empty. eg.
(!PFResutl.toRange).empty. I tired the below, but it is no
printing Empty if the range is empty it just prints blank line.
if (!(!PFResutl.toRange).empty) { writeln("Empty"); }
From,
Vino.B
I thought every range at the lowest level has an `empty`
property. So, in this case, it would be:
if (PFResutl.toRange.empty)
{
writeln("Empty");
}
Re: Garbage collected pointers?
On Friday, 2 March 2018 at 08:44:53 UTC, Gary Willoughby wrote: It would be interesting to test whether those methods handle these scenarios. Yeah, it doesn't work. https://dpaste.dzfl.pl/55116efd0c9c
Re: Garbage collected pointers?
On Thursday, 1 March 2018 at 12:20:08 UTC, Steven Schveighoffer wrote: On 3/1/18 7:05 AM, Gary Willoughby wrote: On Thursday, 1 March 2018 at 10:10:27 UTC, John Burton wrote: My question is how do I tell if a pointer is "garbage collected" or not? You could try `GC.addrOf()` or `GC.query()` in core.memory. I was going to say this, but then I realized, it's not that the pointer points at GC-allocated memory, but that the pointer itself is stored in a location that is scanned by the GC. That's not as easy to figure out, as you have to look at stacks, added ranges, etc. -Steve It would be interesting to test whether those methods handle these scenarios.
Re: Garbage collected pointers?
On Thursday, 1 March 2018 at 10:10:27 UTC, John Burton wrote: My question is how do I tell if a pointer is "garbage collected" or not? You could try `GC.addrOf()` or `GC.query()` in core.memory.
Re: Does dmd not always compile all of the source code?
On Wednesday, 6 December 2017 at 16:47:17 UTC, A Guy With a
Question wrote:
abstract class Test(T)
{
private:
T thing;
public:
this(T theThing)
{
thing = theThing;
thisdoesnotexist(); // expect compiler error right here
}
}
...but this compiles just fine.
It's because it's not being used in your program. How can the
compiler compile it without knowing what T would be?
When you do this:
class Test2
: Test!int
{
this(int thing)
{
super(thing);
}
}
You are suppling T and now it is compiled and an error raised.
Re: What does ! mean?
On Wednesday, 27 September 2017 at 14:23:01 UTC, Ky-Anh Huynh wrote: Can you please explain and give any link where I can learn more about these things? Thanks a lot. http://nomad.so/2013/07/templates-in-d-explained/
Re: C style 'static' functions
On Wednesday, 19 July 2017 at 07:22:48 UTC, John Burton wrote: In C++ I could use static or an anonymous namespace for implementation functions, but there doesn't seem to be anything similar in D. Is there any way to achieve what I want in D (Private implementation functions) Try the package keyword: https://dlang.org/spec/attribute.html#visibility_attributes
Re: Generic operator overloading for immutable types?
On Tuesday, 13 June 2017 at 11:36:45 UTC, Steven Schveighoffer
wrote:
Nope, const works just fine. A clue is in your return type --
it's not inout!
This should work:
public Rational opBinary(string op)(Rational rhs) const
If Rational had any indirections, then inout would be required,
and your signature wouldn't work (because you can't convert an
inout(SomethingWithPointers) to SomethingWithPointers).
Why do I need to make the member function const, but not the
parameter? Because the parameter is taken by value, 'this' is a
reference.
-Steve
Is it possible for the `result` variable in the following code to
be returned as an immutable type if it's created by adding two
immutable types?
import std.stdio;
struct Rational
{
public long numerator;
public long denominator;
public inout Rational opBinary(string op)(inout(Rational) other)
const
{
static if (op == "+")
{
return inout(Rational)(0, 0);
}
else
{
static assert(0, "Operator '" ~ op ~ "' not
implemented");
}
}
}
unittest
{
auto baz= immutable(Rational)(1, 3);
auto qux= immutable(Rational)(1, 6);
auto result = baz + qux;
writeln(typeof(result).stringof); // Result is not immutable!
}
Re: Generic operator overloading for immutable types?
On Monday, 12 June 2017 at 20:10:17 UTC, H. S. Teoh wrote: Therefore, nowadays I always recommend writing parenthesis with type modifiers, so that the intent it unambiguous, i.e., always write `inout(Rational)` rather than `inout Rational`, unless you intend for `inout` to apply to the function rather than the return value. (And I apologize for the slip-up in my code example above, where I failed to do this for the function parameter.) T Ok, thanks.
Re: Generic operator overloading for immutable types?
On Monday, 12 June 2017 at 19:36:52 UTC, H. S. Teoh wrote:
On Mon, Jun 12, 2017 at 07:38:44PM +, Gary Willoughby via
Digitalmars-d-learn wrote:
In the following code is there any way to make the `opBinary`
method generic to be able to accept immutable as well as a
standard type? The code currently passes the unit test but I
wonder if I could get rid of the duplication to overload the
operator? I'm failing badly.
This is what inout was designed for:
public inout Rational opBinary(string op)(inout Rational rhs)
{
static if (op == "+")
{
return inout(Rational)(0, 0);
}
else
{
static assert(0, "Operator '" ~ op ~ "' not
implemented");
}
}
That should do the trick.
T
Quick question about the signature, if I change it to (note the
parens):
public inout(Rational) opBinary(string op)(inout(Rational) rhs)
It no longer works, why is that?
Re: Generic operator overloading for immutable types?
I don't know how H. S. Teoh managed to answer 'before' I posted but thanks guys! :)
Generic operator overloading for immutable types?
In the following code is there any way to make the `opBinary`
method generic to be able to accept immutable as well as a
standard type? The code currently passes the unit test but I
wonder if I could get rid of the duplication to overload the
operator? I'm failing badly.
import std.stdio;
struct Rational
{
public long numerator;
public long denominator;
public immutable Rational opBinary(string op)(immutable Rational
rhs)
{
static if (op == "+")
{
return Rational(0, 0);
}
else
{
static assert(0, "Operator '" ~ op ~ "' not
implemented");
}
}
public Rational opBinary(string op)(Rational rhs)
{
static if (op == "+")
{
return Rational(0, 0);
}
else
{
static assert(0, "Operator '" ~ op ~ "' not
implemented");
}
}
}
unittest
{
auto foo = Rational(1, 3);
auto bar = Rational(1, 6);
writefln("%s", foo + bar);
auto baz = immutable Rational(1, 3);
auto qux = immutable Rational(1, 6);
writefln("%s", baz + qux);
}
Re: The syntax of sort and templates
On Friday, 26 May 2017 at 09:59:26 UTC, zakk wrote: 1) Why is D making using of the binary ! operator, which as far as I understand introduces a template? The exclamation mark here is not a binary operator, it's used in D templates to define where compile-time parameters are. 2) Why is a template needed here? It's a template so you can use differently typed ranges. Remember a range is an interface and very different types can implement it. 3) It seems to me like the argument passed to the template is a lambda expression. I only know about templates taking types as argument. What's going on? The function parameter is defined as an alias which is also valid at compile-time. https://dlang.org/phobos/std_algorithm_sorting.html#sort
Re: Why would an initialised struct pointer field be null in the struct's destructor?
On Saturday, 20 May 2017 at 12:25:39 UTC, Stanislav Blinov wrote: Oof. Dangerous stuff. :) Thanks for the heads up but I think I'm covering all cases in my main code.
Re: Why would an initialised struct pointer field be null in the struct's destructor?
On Saturday, 20 May 2017 at 11:15:57 UTC, Moritz Maxeiner wrote: Because `element = tmp` destroys `element`, which you allocated filled with zeroes. The destructor will run for each `element`. Right, I get it because the destructors running on the struct that is being replaced. Doh!
Why would an initialised struct pointer field be null in the struct's destructor?
In the following code, the `_foo` pointer (of the Foo struct) is
null in the first call to the destructor. Why is this? I think
it's got something to do with the foreach loop but I'm not sure.
Any ideas?
import std.stdio;
import core.stdc.stdlib : malloc, calloc, free;
struct Foo
{
public int* _foo;
public this(int n)
{
this._foo = cast(int*) malloc(int.sizeof);
writefln("ctor: %x", this._foo);
}
public this(this)
{
writefln("post blit: %x", this._foo);
}
public ~this()
{
// Why is this._foo null here???
writefln("dtor: %x", this._foo);
}
}
struct Bar
{
private Foo[] _data;
public this(int n)
{
this._data = (cast(Foo*) calloc(n, Foo.sizeof))[0 .. n];
foreach(ref element; this._data)
{
auto tmp = Foo(1);
element = tmp;
}
}
}
void main(string[] args)
{
auto bar = Bar(1);
}
Re: How to check a struct exists at a particular memory address?
On Thursday, 18 May 2017 at 21:09:06 UTC, Igor wrote: On Thursday, 18 May 2017 at 20:20:47 UTC, Gary Willoughby wrote: This might be a really silly question but: I've allocated some memory like this (Foo is a struct): this._data = cast(Foo*) calloc(n, Foo.sizeof); How can I then later check that there is a valid Foo at `this._data` or `this._data + n`? Well... I think the right answer is that everything you do with memory should be very deterministic so you should just know where is what and not have a need to check :). Agreed. I think I'll re-visit the design.
How to check a struct exists at a particular memory address?
This might be a really silly question but: I've allocated some memory like this (Foo is a struct): this._data = cast(Foo*) calloc(n, Foo.sizeof); How can I then later check that there is a valid Foo at `this._data` or `this._data + n`?
Re: is char[] faster than string?
On Wednesday, 5 April 2017 at 21:58:16 UTC, Inquie wrote: What I am looking for is something like StringBuilder in C#. std.array.appender
Re: Memory Allocation
On Wednesday, 29 March 2017 at 19:19:48 UTC, Enigma wrote: I have a memory buffer allocated using different methods. It is simply a pointer and a size. I would like to be able to manage this buffer by treating it as a memory pool or heap. I think I can use allocators to do this but not sure how. You can re-task the GC to use an arena if that's suitable: https://bitbucket.org/infognition/dstuff/src/1dca752af1021ed5998bb041004465674695113f/gcarena.d?fileviewer=file-view-default
Re: how to define my own traits
On Sunday, 26 March 2017 at 23:25:49 UTC, XavierAP wrote:
I've looked into Phobos to emulate it when defining my own
trait template, and when I see this:
module std.range.primitives;
// ...
template isInputRange(R)
{
enum bool isInputRange = is(typeof(
(inout int = 0)
{
R r = R.init; // can define a range object
if (r.empty) {} // can test for empty
r.popFront; // can invoke popFront()
auto h = r.front; // can get the front of the range
}));
I wonder, why that unused parameter (inout int = 0)?
In my project () { /* ... */ } works the same for a custom
trait.
Even Andrei was baffled:
http://forum.dlang.org/thread/nepm2k$311l$1...@digitalmars.com
Re: constraint on variadic template
On Wednesday, 7 December 2016 at 16:35:52 UTC, Alex wrote:
mixin template S(T...)
{
void run()
{
foreach(s; T)
{
static assert(__traits(hasMember, s, "run"));
}
}
}
How to formulate the check inside the foreach as a template
constraint with
mixin template S(T...) if(???)
Will some like this work?
import std.range.primitives;
mixin template S(T...) if(__traits(hasMember,
ElementType!(T), "run"))
{
...
}
https://dlang.org/phobos/std_range_primitives.html#ElementType
What is the simplest way of doing @nogc string concatenation?
What is the simplest way of doing @nogc string concatenation?
Re: Can someone please explain why the following assertion fails?
On Tuesday, 1 November 2016 at 14:06:08 UTC, Steven Schveighoffer
wrote:
On 10/31/16 3:08 PM, Gary Willoughby wrote:
Can someone please explain why the following assertion fails?
import std.stdio;
import std.conv;
void main(string[] args)
{
auto x = 1;
assert(hashOf(x.to!(string)) == hashOf(x.to!(string)));
}
Thanks.
IMO, it shouldn't. A string's "value" has nothing to do with
it's location.
-Steve
It definitely is surprising. I'll raise an issue and see what
others think.
https://issues.dlang.org/show_bug.cgi?id=16654
Re: Can someone please explain why the following assertion fails?
On Monday, 31 October 2016 at 22:10:30 UTC, Ali Çehreli wrote:
On 10/31/2016 12:08 PM, Gary Willoughby wrote:
Can someone please explain why the following assertion fails?
import std.stdio;
import std.conv;
void main(string[] args)
{
auto x = 1;
assert(hashOf(x.to!(string)) == hashOf(x.to!(string)));
}
Thanks.
I think you need TypeInfo.getHash.
https://dlang.org/phobos/object.html#.TypeInfo.getHash
import std.conv;
auto myHashOf(T)(auto ref T value) {
return typeid(T).getHash();
}
void main() {
auto x = 1;
auto s = "1";
assert(myHashOf(x.to!string) == myHashOf(x.to!string));
assert(myHashOf(s) == myHashOf(s));
assert(myHashOf(s) == myHashOf(x.to!string));
}
Ali
Thanks but `TypeInfo.getHash` is not @nogc. Looks like I'll have
to roll my own.
Re: Can someone please explain why the following assertion fails?
On Monday, 31 October 2016 at 19:24:13 UTC, Ali Çehreli wrote: On 10/31/2016 12:08 PM, Gary Willoughby wrote: [...] Because it considers the .ptr property of arrays as well: https://github.com/dlang/druntime/blob/master/src/core/internal/hash.d#L61 [...] Ah right. Is there an alternative built-in, generic, nogc hash function that would return the same values for Strings?
Re: Can someone please explain why the following assertion fails?
On Monday, 31 October 2016 at 19:08:50 UTC, Gary Willoughby wrote:
Can someone please explain why the following assertion fails?
import std.stdio;
import std.conv;
void main(string[] args)
{
auto x = 1;
assert(hashOf(x.to!(string)) == hashOf(x.to!(string)));
}
Thanks.
DMD64 D Compiler v2.072.0
Copyright (c) 1999-2016 by Digital Mars written by Walter Bright
Ubuntu 16.04
Can someone please explain why the following assertion fails?
Can someone please explain why the following assertion fails?
import std.stdio;
import std.conv;
void main(string[] args)
{
auto x = 1;
assert(hashOf(x.to!(string)) == hashOf(x.to!(string)));
}
Thanks.
Re: What exactly does the compiler switch -betterC do?
On Tuesday, 20 September 2016 at 13:23:35 UTC, Jacob Carlborg wrote: On 2016-09-19 23:09, Gary Willoughby wrote: $ rdmd --build-only --force -betterC -de -O -inline -release -w test.d $ nm test Indeed. I just noticed now that there's a difference between 2.070.0 and 2.071.0. I get 4 symbols with 2.070.0 and 2428 with 2.071.0. I would say it's a bug. Filed: https://issues.dlang.org/show_bug.cgi?id=16547
Re: What exactly does the compiler switch -betterC do?
On Monday, 20 June 2016 at 06:35:32 UTC, Jacob Carlborg wrote:
On 2016-06-19 21:53, Gary Willoughby wrote:
When compiling, what exactly does the -betterC flag do? The
command help
says "omit generating some runtime information and helper
functions" but
what does this really mean? Is there any specifics somewhere?
It is intended to allow you to link an application without
druntime. A Hello World using "extern(C) main" and printing
using "printf" contains the following symbols on OS X:
00a8 S _D4main12__ModuleInfoZ
0068 T _D4main15__unittest_failFiZv
0018 T _D4main7__arrayZ
0040 T _D4main8__assertFiZv
00b5 s _TMP1
U __d_arraybounds
U __d_assert
U __d_unittest
T _main
U _printf
If compiled with -betterC, it contains these:
T _main
U _printf
I get significantly more symbols than that when compiling the
following program any idea why?
import core.stdc.stdio;
extern(C) void main()
{
printf("Hello World!\n");
}
$ rdmd --build-only --force -betterC -de -O -inline -release -w
test.d
$ nm test
Re: Metaprogramming with traits
On Thursday, 15 September 2016 at 22:05:55 UTC, Ram_B wrote: test.d(33): Error: variable f cannot be read at compile time test.d(33): Error: string expected as second argument of __traits hasMember instead of __error test.d(46): Error: template instance test.A.t!(B) error instantiating Maybe Array!(string) can't be use in compile-time code?
Re: Metaprogramming with traits
On Thursday, 15 September 2016 at 15:07:09 UTC, Ram_B wrote:
How i can get fields of derived classes in runtime? This not
works
What about something like this:
import std.traits;
import std.stdio;
class A {
int a,b;
this(){}
void fields(this T)(){
writeln(FieldNameTuple!(T));
foreach(Class; TransitiveBaseTypeTuple!(T)) {
writeln(FieldNameTuple!(Class));
}
}
}
class B : A{
int c;
this(){}
}
class C : B{
int d;
this(){}
}
void main(){
C c = new C();
c.fields();
}
Re: How to add nogc to delegate
On Thursday, 11 August 2016 at 05:12:39 UTC, ag0aep6g wrote: On 08/11/2016 06:15 AM, Engine Machine wrote: void foo(@nogc void delegate()) doesn't work. Put it after the parameter list, like so: void foo(void delegate() @nogc) You may also need to add the scope keyword too. Reference: http://forum.dlang.org/thread/zaxaqgeeenwypmijr...@forum.dlang.org
Re: I need a @nogc version of hashOf(). What are the options?
On Sunday, 7 August 2016 at 18:37:19 UTC, ag0aep6g wrote: On 08/07/2016 07:10 PM, ag0aep6g wrote: https://github.com/dlang/druntime/pull/1624 Has been merged. Is going to be part of 2.072. Very cool! MurmurHash3 is a great addition too. Thanks guys.
I need a @nogc version of hashOf(). What are the options?
I need a @nogc version of hashOf(). Here's one i'm currently using but it's not marked as @nogc. https://github.com/dlang/druntime/blob/master/src/object.d#L3170 What are the options now? Is there anything D offers that I could use? I need a function that takes a variable of any type and returns a numeric hash.
Re: Endiannes & Splitting Values
On Thursday, 7 July 2016 at 10:48:56 UTC, Lodovico Giaretta wrote:
On Thursday, 7 July 2016 at 10:45:12 UTC, Gary Willoughby wrote:
On Thursday, 7 July 2016 at 08:21:53 UTC, Lodovico Giaretta
wrote:
Are you sure that this works in both big-endian and
little-endian systems?
It shouldn't matter. You're just interested in the high and
low 4 byte chunks (which are to be interpreted as an int)
which will return in the relevant endianess of your machine.
But are the high 4 bytes the first 4 or the second 4? It
depends on endianness. So your high and low variables may be
switched, if I understand correctly.
Ah, I see. You could modify it like this:
union Value
{
ulong full;
static struct Bits
{
version (BigEndian)
{
uint high;
uint low;
}
else
{
uint low;
uint high;
}
}
Bits bits;
alias bits this;
this(ulong value)
{
this.full = value;
}
}
Re: Endiannes & Splitting Values
On Thursday, 7 July 2016 at 08:21:53 UTC, Lodovico Giaretta wrote: Are you sure that this works in both big-endian and little-endian systems? It shouldn't matter. You're just interested in the high and low 4 byte chunks (which are to be interpreted as an int) which will return in the relevant endianess of your machine.
Re: Endiannes & Splitting Values
On Wednesday, 6 July 2016 at 21:44:37 UTC, BitGuy wrote:
I'm trying to implement a feistel cipher that'll give the same
results regardless of the endianness of the machine it runs on.
To make the cipher I need to split a 64bit value into two 32bit
values, mess with them, and then put them back together. I can
think of a few ways to split a 64bit value with versions or the
endianness functions in bitmanip but it all seems pretty messy
for just wanting to split a value... I'm thinking maybe I can
just cast and bitshift so I can forget about the endianness but
I'm not really sure about the casting down rules and if that'd
work?
What about something like:
import std.stdio;
union Value
{
ulong full;
static struct Bits
{
uint high;
uint low;
}
Bits bits;
alias bits this;
this(ulong value)
{
this.full = value;
}
}
void main(string[] args)
{
auto value = Value(77309411348);
writefln("%s, (%b)", value.high, value.high);
writefln("%s, (%b)", value.low, value.low);
writefln("%s, (%b)", value.full, value.full);
}
Re: Is there anyway to make opApply @nogc?
On Wednesday, 22 June 2016 at 13:36:54 UTC, Marc Schütz wrote:
On Tuesday, 21 June 2016 at 19:21:01 UTC, Gary Willoughby wrote:
Right ok, thanks! It doesn't seem to help though as the
compiler complains about it being not @nogc.
You probably need to declare the delegate and opApply() itself
as @nogc, too:
int opApply(scope int delegate(int) @nogc dg) @nogc { }
That fixed it, thanks all for your help. :)
Re: Is there anyway to make opApply @nogc?
On Tuesday, 21 June 2016 at 12:53:11 UTC, Adam D. Ruppe wrote: On Tuesday, 21 June 2016 at 12:48:04 UTC, Gary Willoughby wrote: I have no idea what that means. Can anyone shed more light on this, please? So when you use local variables in a delegate, the compiler usually makes a copy of them just in case the delegate gets saved for later. When you mark it scope, you promise that you won't save it for later, so the compiler skips making the copy. Right ok, thanks! It doesn't seem to help though as the compiler complains about it being not @nogc.
Re: Is there anyway to make opApply @nogc?
On Monday, 20 June 2016 at 15:27:32 UTC, Adam D. Ruppe wrote: On Monday, 20 June 2016 at 15:13:53 UTC, Gary Willoughby wrote: I think the problem is that the delegate which is required by opApply is allocated using the GC. make the delegate in opApply scope int opApply(scope int delegate(whatever) dg) I'm still not sure what this achieves. The description on the stackoverflow question reads: "And when the compiler sees this on delegates, it will avoid allocating a closure when taking the address of a local function. This is essential in opApply loops." I have no idea what that means. Can anyone shed more light on this, please?
Re: Is there anyway to make opApply @nogc?
On Monday, 20 June 2016 at 15:47:44 UTC, Gary Willoughby wrote: On Monday, 20 June 2016 at 15:27:32 UTC, Adam D. Ruppe wrote: On Monday, 20 June 2016 at 15:13:53 UTC, Gary Willoughby wrote: I think the problem is that the delegate which is required by opApply is allocated using the GC. make the delegate in opApply scope int opApply(scope int delegate(whatever) dg) What effect does this have? and how does it beat the GC? Found the explanation here: http://stackoverflow.com/questions/4711309/meaning-of-scope-in-d-for-a-parameter I give it a go. Thanks.
Re: Is there anyway to make opApply @nogc?
On Monday, 20 June 2016 at 15:27:32 UTC, Adam D. Ruppe wrote: On Monday, 20 June 2016 at 15:13:53 UTC, Gary Willoughby wrote: I think the problem is that the delegate which is required by opApply is allocated using the GC. make the delegate in opApply scope int opApply(scope int delegate(whatever) dg) What effect does this have? and how does it beat the GC?
Re: Is there anyway to make opApply @nogc?
On Monday, 20 June 2016 at 14:34:33 UTC, Mathias Lang wrote: Can't `opApply` with `auto` return type works since it infers attributes ? I think the problem is that the delegate which is required by opApply is allocated using the GC.
Is there anyway to make opApply @nogc?
Is there any way to make opApply @nogc? or provide the same
foreach functionality without implementing a range interface?
I want to iterate over a piece of memory using a pointer. I
thought about using opSlice but that doesn't provide information
for an index in a foreach loop.
auto opSlice()
{
return this._pointer[0 .. size];
}
Anyone got any ideas?
What exactly does the compiler switch -betterC do?
When compiling, what exactly does the -betterC flag do? The command help says "omit generating some runtime information and helper functions" but what does this really mean? Is there any specifics somewhere?
Re: Why do I get this error when casting to an immutable or shared byRef return type?
On Sunday, 19 June 2016 at 10:35:59 UTC, Gary Willoughby wrote:
...
A more correct example:
import core.stdc.stdlib;
import std.traits;
ref T foo(T)()
{
alias Type = Unqual!(T);
Type* foo = cast(Type*) malloc(Type.sizeof * 8);
return *foo;
}
void main(string[] args)
{
// Works!
auto bar = foo!(int)();
// Works!
auto bar = foo!(const(int))();
// Error: cast(immutable(int))*foo is not an lvalue
auto bar = foo!(immutable(int))();
// Error: cast(shared(int))*foo is not an lvalue
auto bar = foo!(shared(int))();
}
Why do I get this error when casting to an immutable or shared byRef return type?
In the following code, the `foo` function doesn't work when
casting to an immutable or shared type. Can anyone please explain
what is happening here? Is there any way of returning such
variables byRef from a malloc'd chunk of memory?
import core.stdc.stdlib;
ref T foo(T)()
{
int* foo = cast(int*) malloc(int.sizeof * 8);
return *foo;
}
void main(string[] args)
{
// Works!
auto bar = foo!(int)();
// Works!
auto bar = foo!(const(int))();
// Error: cast(immutable(int))*foo is not an lvalue
auto bar = foo!(immutable(int))();
// Error: cast(shared(int))*foo is not an lvalue
auto bar = foo!(shared(int))();
}
Is it possible to create a static factory method on a templated struct?
I've tried the following code and I get the error:
Error: template Foo(A) does not have property 'of'
struct Foo(A)
{
private int _foo;
@disable this();
public this(int foo)
{
this._foo = foo;
}
public static auto of(B)()
{
return Foo!(B)(8);
}
}
void main(string[] args)
{
auto foo = Foo.of!(string);
}
Is it possible to even have static methods on structs like this?
What am I doing wrong?
Is there a more elegant way of testing T for multiple types?
Here I'm testing T is either a class or interface:
void foo(T)(T bar) if (is(T == class) || is(T == interface))
{
...
}
Is there a more elegant way of testing T for multiple types?
Because it doesn't scale well if I need to add more.
I would love to use something like this:
void foo(T)(T bar) if (T in [class, interface])
{
...
}
Is something like this currently possible using type tuples?
Re: Default initialization of structs?
On Friday, 17 June 2016 at 10:53:40 UTC, Lodovico Giaretta wrote:
struct Foo(T)
{
private int _bar = 1;
this(int bar)
{
this._bar = bar;
}
}
auto foo = Foo!(string)();
This should do the trick.
Thanks, I forgot to mention I'm also doing lots of other stuff in
the constructor to private fields too.
struct Foo(T)
{
private int _bar;
private void* _baz;
this(int bar = 8)
{
this._bar = bar;
this._baz = malloc(this._bar);
}
}
So I have to at least run a constructor.
Default initialization of structs?
I have a struct where I need to perform default initialization of
some members but the compiler doesn't allow to define a default
constructor which allow optional arguments.
struct Foo(T)
{
private int _bar;
this(int bar = 1)
{
this._bar = bar;
}
}
auto foo = Foo!(string) // error
Are there any patterns or idioms I could use to get the desired
result? Or is it just the case if I use a constructor I have to
pass values to it?
Re: Creating a reference counted type?
On Sunday, 12 June 2016 at 15:05:53 UTC, ketmar wrote: this is basically how refcounted structs are done. note that i just typed the code into reply box, so it may not compile or contain some small bugs, but i think you got the idea. Thanks for the replies guys.
Re: Creating a reference counted type?
On Sunday, 12 June 2016 at 14:45:12 UTC, ketmar wrote: ahem... wut?! we have one copy of our struct freed half the way, and another copy has refcount of 2, so it won't be freed at all. it doesn't so innocent as it looks: we may try to use `f` in `main`... just to find out that resources was mysteriously freed, and refcount is total garbage. Hmmm. I thought it looked *too* simple. Have you any idea if there is a simple solution to this?
Re: Creating a reference counted type?
On Sunday, 12 June 2016 at 14:29:19 UTC, Gary Willoughby wrote: Another thing that is puzzling me is that when creating an instance of the above struct and passing as an argument to a function, the copy constructor is called and the reference count is incremented. This is expected. However, when the function returns, the destructor is called (on the copy) and the reference count lowered. How does the original instance know of the updated reference count from the copy? Actually, this doesn't puzzle me at all! I think I must be tired. Ignore this paragraph, it doesn't make sense. lol.
Creating a reference counted type?
I'm wondering if it's this easy to create a reference counted
type:
struct Foo
{
int _refCount = 1;
this(...)
{
// allocate resources, etc.
}
this(this)
{
this._refCount++;
}
~this()
{
this._refCount--;
if (this._refCount == 0)
{
// free resources.
}
}
}
Are there any other considerations I need to handle?
Another thing that is puzzling me is that when creating an
instance of the above struct and passing as an argument to a
function, the copy constructor is called and the reference count
is incremented. This is expected. However, when the function
returns, the destructor is called (on the copy) and the reference
count lowered. How does the original instance know of the updated
reference count from the copy?
Re: D, GTK, Qt, wx,…
On Saturday, 4 June 2016 at 08:27:53 UTC, Russel Winder wrote: On Sun, 2016-05-29 at 14:01 +0200, Jordi Sayol via Digitalmars-d-learn wrote: […] https://github.com/nomad-software/tkd I am not a great fan of tk even in Python. It is true that Tk is everywhere and so meets the portability requirement, but I would still go with Qt (well QML anyway) in preference. I'm the author of Tkd and I would always try and choose another framework before Tkd. ;) Simply because others give you much more control over your UI. That said, Tkd is invaluable for quick and dirty GUI apps or prototypes. Choose the right tool for the job, etc.
Re: Is there any overhead iterating over a pointer using a slice?
On Tuesday, 31 May 2016 at 20:52:20 UTC, Johan Engelen wrote:
On Tuesday, 31 May 2016 at 18:55:18 UTC, Gary Willoughby wrote:
If I have a pointer and iterate over it using a slice, like
this:
T* foo =
foreach (element; foo[0 .. length])
{
...
}
Is there any overhead compared with pointer arithmetic in a
for loop?
Use the assembly output of your compiler to check! :-) It's
fun to look at.
For example, with GDC:
http://goo.gl/Ur9Srv
No difference.
cheers,
Johan
That's pretty nice.
Is there any overhead iterating over a pointer using a slice?
In relation to this thread:
http://forum.dlang.org/thread/ddckhvcxlyuvuiyaz...@forum.dlang.org
Where I asked about slicing a pointer, I have another question:
If I have a pointer and iterate over it using a slice, like this:
T* foo =
foreach (element; foo[0 .. length])
{
...
}
Is there any overhead compared with pointer arithmetic in a for
loop?
Re: How to hash any type to an integer?
On Sunday, 29 May 2016 at 16:26:58 UTC, Seb wrote: On Sunday, 29 May 2016 at 11:05:21 UTC, Gary Willoughby wrote: I'm currently implementing a hash map as an exercise and wondered if there is a built-in function I could use to hash keys effectively? What I'm looking for is a function that hashes any variable (of any type) to an integer. I've been looking at the `getHash` function of the `TypeInfo` class but that only seems to return the passed pointer. Any ideas? How about hashOf? https://dlang.org/phobos/object.html#.hashOf Awesome, thanks. Can't believe I missed that.
How to hash any type to an integer?
I'm currently implementing a hash map as an exercise and wondered if there is a built-in function I could use to hash keys effectively? What I'm looking for is a function that hashes any variable (of any type) to an integer. I've been looking at the `getHash` function of the `TypeInfo` class but that only seems to return the passed pointer. Any ideas?
Re: Is there a way to clear an OutBuffer?
On Monday, 23 May 2016 at 03:03:12 UTC, Jon Degenhardt wrote:
Currently not possible. Enhancement request perhaps?
Looking at the implementation, setting its 'offset' member
seems to work. Based on example from documentation:
import std.outbuffer;
void main() {
OutBuffer b = new OutBuffer();
b.writefln("a%sb", 16);
assert(b.toString() == "a16b\n");
b.offset = 0;
b.writefln("a%sb", 16);
assert(b.toString() == "a16b\n");
}
Bug report perhaps? :)
Ali
Thanks. Enhancement request:
https://issues.dlang.org/show_bug.cgi?id=16062
Is there a consensus on this? Does this really need a clear
method seeing as though you can reset the offset directly?
Re: Is there an easy way to convert a pointer to malloc'd memory to an array?
On Tuesday, 24 May 2016 at 18:43:22 UTC, Adam D. Ruppe wrote: On Tuesday, 24 May 2016 at 18:42:41 UTC, Gary Willoughby wrote: I have a T* pointer to the start of a malloc'd chunk of memory, the type T and the number of T's stored in the chunk. Is there an efficient way of converting this information to a D array of type T[] or even T[n]? Slice it: T[] = t[0 .. n]; That! ...is amazing!
Is there an easy way to convert a pointer to malloc'd memory to an array?
I have a T* pointer to the start of a malloc'd chunk of memory, the type T and the number of T's stored in the chunk. Is there an efficient way of converting this information to a D array of type T[] or even T[n]?
Re: D equivalent of C++ bind ?
On Tuesday, 10 May 2016 at 09:39:53 UTC, chmike wrote: Is there an equivalent in D of the C++11 std.bind template class See http://dlang.org/phobos/std_functional.html#partial
Re: Accepting function or delegate as function argument
On Wednesday, 4 May 2016 at 15:23:20 UTC, Rene Zwanenburg wrote:
On Wednesday, 4 May 2016 at 14:54:39 UTC, chmike wrote:
Two constructors, one accepting a function and the other one
accepting a delegate would do the job for the API. Is there a
simple method to convert a function pointer into a delegate
pointer that is also efficient ?
http://dlang.org/phobos/std_functional.html#.toDelegate
You can also make your constructor a template, constrain it on
isCallable if you wish, and then use toDelegate. If the
argument is already a delegate toDelegate will avoid doing
extra work.
import std.functional;
import std.stdio;
import std.traits;
class Foo(K,T)
{
private T delegate(K) m_factory;
public this(T)(T factory) if (isCallable!(T))
{
this.m_factory = toDelegate(factory);
}
public T bar(K key)
{
return this.m_factory(key);
}
}
string dummyFactory(string key)
{
return "Hello " ~ key;
}
void main()
{
auto foo = new Foo!(string, string)();
writeln(foo.bar("world"));
}
Re: D GUI Toolkit Comparison
On Friday, 29 April 2016 at 13:52:59 UTC, Nordlöw wrote:
Could somebody briefly outline the different GUI toolkits
available in D and how they differ especially in terms of
cleverly the make use of all idioms available in the language
aswell as in Phobos.
For instance: DlangUI and Adams D Ruppe's `simpledisplay`
https://wiki.dlang.org/GUI_Libraries
I'm the author of Tkd[1] and wrote it to learn D in more depth
and really enjoyed the flexibility of generic
classes/functions/interfaces and mixins. Because Tkd is based on
Tcl/Tk it was really hard to map the Tcl language and Tk toolkit
to a sensible type hierarchy using inheritance. Using D gave me
the opportunity to think a bit differently and compose types more
simply while modeling the problem in a more intelligent way. I'm
bias, but I love the simplicity of the finished code.
A pattern I used throughout was this:
class Foo : Bar
{
public auto baz(this T)(...)
{
...
return cast(T) this;
}
}
Which allows chaining of methods with those of parent and child
types, i.e:
import tkd.tkdapplication;
class Application : TkdApplication
{
private void exitCommand(CommandArgs args)
{
this.exit();
}
override protected void initInterface()
{
auto frame = new Frame(2, ReliefStyle.groove)
.pack(10);
auto label = new Label(frame, "Hello World!")
.pack(10);
auto exitButton = new Button(frame, "Exit")
.setCommand()
.pack(10);
}
}
void main(string[] args)
{
auto app = new Application();
app.run();
}
[1]: https://github.com/nomad-software/tkd
Re: Three Cool Things about D?
On Tuesday, 1 March 2016 at 20:26:36 UTC, Ali Çehreli wrote: On 03/01/2016 12:17 PM, Wulfrick wrote: On Tuesday, 1 March 2016 at 20:15:00 UTC, Wulfrick wrote: It looks like the link in wiki.dlang.org/Videos to Andrei's "Three Cool Things about D" is dead. Do you know of another link? Maybe this? https://www.youtube.com/watch?v=3NihZVcZqto Yes, that should be it. Although, I think he made small improvements to the presentation over time. Ali Here's one from 2010: https://www.youtube.com/watch?v=RlVpPstLPEc=PLummIahGJZ1T5wOzRKO32pm7z0Th9_YYe=3
Re: Printing a C "string" with write(f)ln
On Tuesday, 9 February 2016 at 12:50:27 UTC, Jakob Ovrum wrote:
writefln et al sensibly does *not* assume that a pointer to
char is a C string, for memory safety purposes.
Print the result of std.string.fromStringz[1] instead:
writeln(fromStringz(pString));
writefln("%s", fromStringz(pString));
[1] http://dlang.org/phobos/std_string#fromStringz
Or use `to` like this:
import std.conv;
writefln("%s", pString.to!(string));
Re: Printing a C "string" with write(f)ln
On Tuesday, 9 February 2016 at 16:58:03 UTC, Daniel Kozak wrote:
Or use `to` like this:
import std.conv;
writefln("%s", pString.to!(string));
this will allocate new string which can be performance problem.
Which is good in most cases. It's better to have the GC take care
of the D string instead of worrying about the lifetime of pString.
Re: Printing a C "string" with write(f)ln
On Tuesday, 9 February 2016 at 17:02:28 UTC, Jakob Ovrum wrote: to!string behaving like that was a poor design choice[1]. Please use fromStringz. [1] https://github.com/D-Programming-Language/phobos/pull/1607 It's not a poor design choice. It ensures the string is handled by the D GC instead of the C side freeing it. `fromStringz` and `to!(String)` are for different cases.
Re: How do you check if object o has base type B?
On Thursday, 4 February 2016 at 05:51:22 UTC, Enjoys Math wrote:
Consider:
class C {
}
class B : C {
}
class A : B {
}
class D : C {
}
C[] objList;
how do we test if objLis[k] is of base type "B"?
Ie for [new A(), new B(), new D(), new C()] would give output
[true, true, false, false].
?
Thank you! :D
if (cast(B)objLis[k])
{
// It's an instance.
}
Re: Call D from TCL
On Wednesday, 3 February 2016 at 12:20:42 UTC, Vasileios Anagnostopoulos wrote: Is there any example,framework or tutorial on how to call D from Tcl (write new commands in D for Tcl)? I am on Windows 10 x86_64. thank you. I've created a wrapper around Tcl/Tk to create GUI's here: https://github.com/nomad-software/tkd It uses the library found here: https://github.com/nomad-software/tcltk In the project, I've created a simple interpreter which handles communicating to Tcl here: https://github.com/nomad-software/tkd/blob/master/source/tkd/interpreter/tcl.d There is a method on that class for creating commands for use in Tcl.
Re: Call D from TCL
On Wednesday, 3 February 2016 at 14:19:32 UTC, Vasileios Anagnostopoulos wrote: Thank you very much. I investigate Tcl_CmdProc more closely. On Wed, Feb 3, 2016 at 3:50 PM, Gary Willoughby via Digitalmars-d-learn < digitalmars-d-learn@puremagic.com> wrote: On Wednesday, 3 February 2016 at 12:20:42 UTC, Vasileios Anagnostopoulos wrote: [...] I've created a wrapper around Tcl/Tk to create GUI's here: https://github.com/nomad-software/tkd It uses the library found here: https://github.com/nomad-software/tcltk In the project, I've created a simple interpreter which handles communicating to Tcl here: https://github.com/nomad-software/tkd/blob/master/source/tkd/interpreter/tcl.d There is a method on that class for creating commands for use in Tcl. Here's the reference to the C interface: https://www.tcl.tk/man/tcl/TclLib/contents.htm
Re: What is the best declaration type for a string like parameter?
On Thursday, 28 January 2016 at 15:10:38 UTC, Adam D. Ruppe wrote:
On Thursday, 28 January 2016 at 13:36:46 UTC, Puming wrote:
I searched the forum and found that people use `const(char)[]`
or `in char[]` to accept both string and char[] arguments.
There's also the hyper-generic signatures Phobos uses like
void foo(S)(S s) if(isSomeString!S)
Yep, this is your answer.
void foo(S)(S s) if(isSomeString!S)
{
//use s
}
Call normally as it can implicitly determine the type of S:
foo("bar");
Re: How can i track the GC when it's runing?
On Monday, 25 January 2016 at 09:33:15 UTC, Dsby wrote: I want to know How can i track the GC when it's runing? And Which algorithm is D's GC used,only Scan-Mark? There is a good resource here: https://dlang.org/spec/garbage.html It details compiler flags to use to profile and log the GC usage.
Re: [Dlang] Delegate Syntax Question
On Sunday, 10 January 2016 at 14:32:02 UTC, Jack wrote:
...
Just to make your code a little more clear, try using aliases
when defining delegate parameters. Like this:
alias Action = void delegate();
Then in your code you use the alias, like this:
class Bar()
{
private Action _action;
void setAction(Action d)
{
this._action = d;
}
}
IMHO it makes everything more readable and you only have one
definition of the delegate signature.
Re: GC greediness
On Tuesday, 5 January 2016 at 17:20:07 UTC, Justin Whear wrote: On Tue, 05 Jan 2016 16:07:36 +, Jack Applegame wrote: On a server with 4GB of RAM our D application consumes about 1GB. Today we have increased server memory to 6 Gb and the same application under the same conditions began to consume about 3Gb of memory. Does GC greediness depend on available RAM? My understanding is that the GC won't return collected memory to the OS unless a threshold relative the system total is crossed. You can use GC.minimize() from core.memory to decrease this. This could result in degraded performance. Also see: https://dlang.org/spec/garbage.html
Re: A few range questions
On Tuesday, 5 January 2016 at 18:47:30 UTC, Charles Smith wrote: 1. `arr[].sort` is changing arr in place. Any way to not do that? Use this instead: auto result = sort(arr[].dup); .dup duplicates the array and sort(...) uses the std.algorithm sort and not the built-in array sort method. 2. I noticed that result within `countingSort` is an array of arrays. I thought `chain` would concat them... did I miss something obvious? No idea yet.
Re: Call C function - Access violation
On Sunday, 3 January 2016 at 19:24:46 UTC, TheDGuy wrote:
On Sunday, 3 January 2016 at 13:25:04 UTC, Gary Willoughby
wrote:
On Sunday, 3 January 2016 at 13:23:25 UTC, Gary Willoughby
wrote:
I think I've noticed one problem with the code above. You are
using `text.ptr`. You shouldn't do that because you are
passing a pointer not an array. Just use `text`.
Forget this line, my mistake. Use `toStringz` and pass a
pointer instead of an array.
Hi and thanks for your answer. My code looks now like this:
void main(string[] args){
const(char)* val = "Hello World".std.string.toStringz;
char* result = write(val);
const(char)[] s = cstr2dstr(result);
writeln(s);
readln(); //keep the window open
}
But now i get the error: "function expected before(), not
package std of type void" (refering to line 2).
And if i define the variable 'value' as 'const(char)*' i also
have to rewrite my C-function to accept const(char)*...
Use an import.
import std.string;
import std.conv;
void main(string[] args) {
auto value = toStringz("Hello World");
auto result = write(value);
auto s = to!(string)(result);
writeln(s);
}
Also all string literals in D are zero terminated so you could
write the call like this:
auto result = write("Hello World");
Re: Call C function - Access violation
On Sunday, 3 January 2016 at 12:30:34 UTC, TheDGuy wrote: I get an access violation with this code: ... There are a few things you can do to improve your code to make it easier to debug. 1. When converting a D string to a char pointer for use with C, use `std.string.toStringz`: http://dlang.org/phobos/std_string.html#.toStringz 2. When converting a char pointer to a D string use `std.conv.to!(string)`: http://dlang.org/phobos/std_conv.html#.to 3. Define C-style char pointers in D as `const(char)*`. 4. Don't use the variable name `text` as it conflicts with `std.conv.text`. I think I've noticed one problem with the code above. You are using `text.ptr`. You shouldn't do that because you are passing a pointer not an array. Just use `text`.
Re: Call C function - Access violation
On Sunday, 3 January 2016 at 13:23:25 UTC, Gary Willoughby wrote: I think I've noticed one problem with the code above. You are using `text.ptr`. You shouldn't do that because you are passing a pointer not an array. Just use `text`. Forget this line, my mistake. Use `toStringz` and pass a pointer instead of an array.
Re: Is it possible to elegantly create a range over a binary heap?
On Sunday, 27 December 2015 at 22:42:21 UTC, Ivan Kazmenko wrote: If you implement a struct with range primitives over it, you can use it as a range. See the second code example in std.container.binaryheap's docs at http://dlang.org/phobos/std_container_binaryheap.html#.BinaryHeap. Or do you mean you want to print variables in order without modifying the array? Sounds like this would require at least N log N time and N additional memory for an N-element heap anyway (or quadratic time and constant memory). So, you can just copy the array and exhaust the copied binary heap, getting the same asymptotic complexity: N log N time and N additional memory. Ivan Kazmenko. Thanks. I wanted to iterate through the range without modifying the original array but like you said the only way to do that is by copying the data which is not ideal. std.container.binaryheap looks like it implements the range interface and consumes the original during iteration. I'll probably do that too.
Re: Is it possible to elegantly create a range over a binary heap?
On Monday, 28 December 2015 at 14:05:42 UTC, Ivan Kazmenko wrote: 1. You can find maximum, then second maximum, then third maximum and so on - each in constant memory and linear time. So, if performance is somehow not an issue, there is a way to do it @nogc but in N^2 operations. That's perhaps too much of a performance hit. 2. If you output the whole array anyway, you may sort the array in place. A sorted array obeys the heap property, so subsequent heap operations will still work. That's actually a good idea. Sort it first, and it should still be balanced and correct. Then iteration is easy! 3. The tricky part is when we want to support parallel iteration over the same heap. If we look closely at one iteration of heapsort algorithm, it will perhaps become clear how to output values so that the array is a heap between any two consecutive output operations. At the very least, our heap struct over the array can just track which part of the array is already sorted, and work with it separately. 4. Reading and modifying the heap in parallel at the same time does not look possible anyway, so this is as far as we can get. I'll have to test parallel iteration.
Is it possible to elegantly create a range over a binary heap?
I have a binary tree storing ints implemented using an array. The internal state looks like this: 8,7,6,4,1,3,5,2 When extracting this data, it is returned as 8,7,6,5,4,3,2,1. Is it possible to elegantly add a range on top of the internal state to return the correct value order I would expect when extracting? Is there an algorithm documented somewhere for doing this?
Is this an rvalue reference problem?
See the following code:
import std.stdio;
void foo(ref int x)
{
writefln("%s", x);
}
void main(string[] args)
{
int y = 0;
foo(y++);
}
When compiled it produces this error:
test.d(11): Error: function test.foo (ref int x) is not callable
using argument types (int)
If I remove the post-increment of the y variable if works. Is
this an rvalue reference issue? Would you expect this to work?
Should the error message be a little more helpful?
Re: Is it possible to elegantly create a range over a binary heap?
On Sunday, 27 December 2015 at 17:23:35 UTC, Gary Willoughby wrote: I have a binary tree storing ints implemented using an array. The internal state looks like this: 8,7,6,4,1,3,5,2 When extracting this data, it is returned as 8,7,6,5,4,3,2,1. Is it possible to elegantly add a range on top of the internal state to return the correct value order I would expect when extracting? Is there an algorithm documented somewhere for doing this? Some explanatory reference: https://en.wikipedia.org/wiki/Binary_tree#Arrays
Re: Is this an rvalue reference problem?
On Sunday, 27 December 2015 at 18:54:25 UTC, Adam D. Ruppe wrote: On Sunday, 27 December 2015 at 16:05:39 UTC, Gary Willoughby wrote: [...] Yes, but more than that, what, exactly, would you expect from that? The order of operations with the postfix ++ operator and ref would probably lead to confusing results anyway, so better to disallow it and force you to be a bit more clear with the code. [...] Thanks guys, I thought as much.
Re: TreeViews in tkd
On Thursday, 17 December 2015 at 09:47:42 UTC, TheGag96 wrote: I've been trying to get into tkd to make some GUI apps, since it looked like the simplest/intuitive library out there so far. I've been attempting to use their TreeViews to make interactable lists of things, but it almost looks like there's some missing functionality. I made an issue on GitHub but I'm not sure I'll get anything back, it's been 9 months since the last commit. Has anyone worked with this before and could give me some tips? Thanks! Calm down, lol. There have been no commits for 9 months because as far as i'm aware it's finished and stable. I got your issue this morning and will take a look tonight after work.
Re: How to use readText to read utf16 file?
On Tuesday, 17 November 2015 at 02:40:14 UTC, Domain wrote: How to use readText to read utf16 file? Or other encoding file. Here's a helpful resource when working with text files in D. http://nomad.so/2015/09/working-with-files-in-the-d-programming-language/
Re: @property
On Monday, 9 November 2015 at 22:42:16 UTC, Fyodor Ustinov wrote: If this feature will be removed, it will be very lacking code, like: writeln = "Hello, world!"; :) WBR, Fyodor. The feature is not being removed. Only the @property attribute and compiler check is being removed.
Re: When a variable is passed into a function, is its name kept somewhere for the function to acceess
On Tuesday, 10 November 2015 at 14:14:33 UTC, DlangLearner wrote:
Please enlighten me if this can be done, thanks.
If i understand you, you could use a templated function:
import std.stdio;
void foo(alias a)()
{
writefln("%s was passed in.", a.stringof);
}
void main(string[] args)
{
auto bar = "bar";
foo!(bar);
}
Re: Associative array with duplicated keys?
On Thursday, 5 November 2015 at 10:04:02 UTC, Andrea Fontana wrote: Anyway: are duplicated keys on declaration allowed? IMHO This should at least be a warning.
Re: Capturing __FILE__ and __LINE in a variadic templated function
On Monday, 2 November 2015 at 08:23:16 UTC, Nordlöw wrote: I need `T` to be an alias in order for .stringof to work. typeof(T).stringof
