Re: Mysterious identifier in std.traits.ParameterStorageClassTuple

On Tuesday, 24 July 2018 at 21:05:05 UTC, Jean-Louis Leroy wrote: What is `PT` here: https://github.com/dlang/phobos/blob/master/std/traits.d#L1224 Where does it come from? https://dlang.org/spec/expression.html#is_expression look for 6. is ( Type Identifier == TypeSpecialization )

Re: Determine if CTFE or RT

On Sunday, 24 June 2018 at 19:10:36 UTC, Mr.Bingo wrote: On Sunday, 24 June 2018 at 18:21:09 UTC, rjframe wrote: On Sun, 24 Jun 2018 14:43:09 +, Mr.Bingo wrote: let is(CTFE == x) mean that x is a compile time constant. CTFE(x) converts a x to this compile time constant. Passing any

Re: Quick Refresher book?

On Saturday, 16 June 2018 at 23:33:18 UTC, Aedt wrote: Hello, I was wondering if there's any quick refresher resource to brush up on my D after a long time? Is there a short and quick language reference book like "A Tour of C++"? if you havent seen it yet, there is the dlang tour

Re: Build interface from abstract class

On Tuesday, 29 May 2018 at 19:06:24 UTC, DigitalDesigns wrote: On Monday, 28 May 2018 at 22:15:40 UTC, arturg wrote: this might help you, https://dpaste.dzfl.pl/2cf844a11e3f you can use them to generate the functions as strings. Thanks, So, the problem I'm having is that I cannot use the

Re: Build interface from abstract class

this might help you, https://dpaste.dzfl.pl/2cf844a11e3f you can use them to generate the functions as strings.

Re: Sealed classes - would you want them in D? (v2)

On Thursday, 17 May 2018 at 07:30:58 UTC, KingJoffrey wrote: On Thursday, 17 May 2018 at 06:03:19 UTC, arturg wrote: you could declare the public api of your class inside an actual interface then use it instead of the class, that wont give you access to the private members of the class.

Re: Sealed classes - would you want them in D? (v2)

On Thursday, 17 May 2018 at 05:06:54 UTC, KingJoffrey wrote: If people want to propose putting each class in it's own module, that does not address my requirements, and therefore is not helpful to this discussion. you could declare the public api of your class inside an actual interface

Re: returning and receiving multiple values from a function

On Tuesday, 15 May 2018 at 01:40:50 UTC, timepp wrote: Now C++ allow this in a very clean way: std::tuple foo() { return {128, true, 1.5f}; } auto [value1, value2, value3] = foo(); Would D plan to support that in syntax level? it depends if some dip like

Re: Generating a method using a UDA

On Wednesday, 9 May 2018 at 10:16:22 UTC, Melvin wrote: I'm trying to find a friendly syntax for defining things in a framework. For context, I've been looking into finding a solution for this problem (https://github.com/GodotNativeTools/godot-d/issues/1) on the Godot-D project. I've done

Re: Found on proggit: Krug, a new experimental programming language, compiler written in D

On Thursday, 26 April 2018 at 22:29:46 UTC, Nick Sabalausky (Abscissa) wrote: On 04/26/2018 01:13 PM, arturg wrote: why do people use this syntax? if val == someVal or while val != someVal it makes editing the code harder then if you use if(val == someVal). The theory goes: A. "less

Re: Found on proggit: Krug, a new experimental programming language, compiler written in D

On Thursday, 26 April 2018 at 15:07:37 UTC, H. S. Teoh wrote: On Thu, Apr 26, 2018 at 08:50:27AM +, Joakim via Digitalmars-d wrote: https://github.com/felixangell/krug https://www.reddit.com/r/programming/comments/8dze54/krug_a_systems_programming_language_that_compiles/ It's still too

Re: Delegates and classes for custom code.

On Wednesday, 18 April 2018 at 01:58:40 UTC, arturg wrote: is it this what you want? class A { int a; void delegate() onDraw; this(void delegate() dg) { onDraw = dg; } void drawText(string s) { s.writeln; }

Re: Delegates and classes for custom code.

On Wednesday, 18 April 2018 at 01:12:33 UTC, Chris Katko wrote: That was all pseudo-code typed by hand. I got my code to work today. I don't know if it's the prettiest it can be, but it works: // TESTING ACCESS TO the OWNING function //--- class

Re: Enum and Function Parameters Attributes -- No DIP Required

On Thursday, 12 April 2018 at 08:28:17 UTC, Mike Parker wrote: Around the same time, a Pull Request was created to implement support for UDAs on function parameters [4]. In the comment thread for this PR, Andrei said that he and Walter "agree this can be integrated without a DIP." When he

Re: Recursive attribute for virtual functions?

On Tuesday, 27 March 2018 at 23:34:20 UTC, arturg wrote: On Tuesday, 27 March 2018 at 23:23:38 UTC, ag0aep6g wrote: DMD might accept that, but I don't think it works in a meaningful way. How do you call the @system one? Looks like the @safe one will always be called, even from @system

Re: Recursive attribute for virtual functions?

On Tuesday, 27 March 2018 at 23:23:38 UTC, ag0aep6g wrote: DMD might accept that, but I don't think it works in a meaningful way. How do you call the @system one? Looks like the @safe one will always be called, even from @system code: import std.stdio; void talk() @system {

Re: Recursive attribute for virtual functions?

On Tuesday, 27 March 2018 at 21:25:33 UTC, ag0aep6g wrote: On 03/27/2018 11:10 PM, 12345swordy wrote: Shouldn't it give a warning then? I wouldn't mind a warning, or even an error. Putting both @safe and @system directly on a function is an error, too. shouldn't it create a overload? for

Re: Help with specific template function

On Monday, 26 March 2018 at 06:40:34 UTC, Vladimirs Nordholm wrote: How would I resolve this issue? use the type not the variables: isNumeric!X && isNumeric!Y

Re: how to make private class member private

On Saturday, 17 March 2018 at 14:16:19 UTC, bauss wrote: I don't like the name @deny, personally I would rather see the private attribute changed to something like: private(true) // The member is oly visible to its parent. private(false) // Same as just "private", visible to whole module.

Re: How give a module to a CTFE function

On Monday, 12 March 2018 at 22:34:10 UTC, Xavier Bigand wrote: Ok, it works with the alias, I didn't see the last () in the implementFunctionsOf prototype. Thank you a lot. no problem. :)

Re: How give a module to a CTFE function

On Monday, 12 March 2018 at 22:28:30 UTC, Xavier Bigand wrote: I forgot to precise, that I don't have a main, because I am trying to create an opengl32.dll. This is why I already have a mixin to inject to function definitions in the root scope. you have to pass the string as a template arg

Re: How give a module to a CTFE function

On Monday, 12 March 2018 at 21:00:07 UTC, Xavier Bigand wrote: Hi, I have a CTFE function that I want to make more generic by given it a module as parameter. My actual code looks like : mixin(implementFunctionsOf()); string implementFunctionsOf() { import std.traits; string

context pointer breaks getOverloads, shouldn't it be ignored by it?

void main() { class Foo { void fun(){} } foreach(m; __traits(allMembers, Foo)) foreach(sym; __traits(getOverloads, Foo, m)) { } } this fails with: onlineapp.d(9): Error: no property this for type onlineapp.main.Foo onlineapp.d(9): Error: (Foo).this cannot

Re: is it possible to put some DDOC after auto generated blocks like unittest examples?

On Monday, 5 March 2018 at 14:50:54 UTC, Adam D. Ruppe wrote: No, ddoc does not support that. You might be able to hack it with javascript though. thanks, yeah eigther that or a d script to do some postprocessing, so it can work without javascript.

is it possible to put some DDOC after auto generated blocks like unittest examples?

/// void fun(){} ///$(TABLE $(TR $(TD Back to:) $(TD href="#fun">Declaration) $(TD $(LINK2 #top, Top unittest { } it basically should look like this: Declaration void fun() Example --- --- [Back to:] [Declaration] [Top] and if i replace the embbeded html with $(LINK2 #fun,

Re: isInputRange copied verbatim produces a different result than isInputRange from std.range

On Sunday, 4 March 2018 at 21:47:43 UTC, Jonathan M Davis wrote: On Sunday, March 04, 2018 21:03:23 arturg via Digitalmars-d-learn wrote: isn't this what DIP 1005 tried to solve? No. What DIP 1005 was trying to solve was avoiding having to have imports used by your function signature

Re: Get function argument name?

On Sunday, 4 March 2018 at 21:03:04 UTC, JN wrote: Imagine a function like this: void printValue(T)(string name, T value) { writeln(name, " = ", value); } int x = 10; printValue("x", x); is it somehow possible to convert that printValue into a mixin or something, so I could do something

Re: isInputRange copied verbatim produces a different result than isInputRange from std.range

On Sunday, 4 March 2018 at 19:58:14 UTC, ag0aep6g wrote: On 03/04/2018 08:54 PM, aliak wrote: wait a minute... so I can't use any std.range functions on a type if I add the range primitives as free functions? O.o Yes. In other words: You can't implement range primitives as free functions.

Re: importing std.array: empty in a struct messes things up

On Sunday, 4 March 2018 at 20:07:06 UTC, visitor wrote: On Sunday, 4 March 2018 at 19:53:59 UTC, ag0aep6g wrote: On 03/04/2018 08:45 PM, ag0aep6g wrote: I don't know what's going on here. The error message doesn't make sense to me. Might be a bug in the compiler. This one works: struct

Re: importing std.array: empty in a struct messes things up

I had the same issue, happens with any conflicting selective import. It seems to work if you dont use selective imports, but importing it inside the function if possible is a better option.

Re: Opt-in non-null class references?

On Saturday, 3 March 2018 at 18:28:42 UTC, aliak wrote: On Friday, 2 March 2018 at 19:47:23 UTC, SimonN wrote: If you know of other ways though I'm all ears :) Cheers maybe not exactly what you want, but here are some templates i wrote a while ago which basically are a more flexible form of

Re: Traits redux

On Saturday, 3 March 2018 at 16:20:57 UTC, JN wrote: https://run.dlang.io/gist/ec7008372d60ac52460dd58068f1ca6d?compiler=dmd Why only listUDA2 works and listUDA doesn't? Why do I need to use __traits(getMember again, if I use what I saved in a variable, it doesn't work :( because getUDAs

Re: confused with data types

On Sunday, 18 February 2018 at 13:08:09 UTC, thorstein wrote: On Sunday, 18 February 2018 at 12:51:04 UTC, thorstein wrote: // Solution 1 foreach(row; arr) { foreach(col; row) { col[] *= skalar; } } return arr; // Solution 2 import std.array; return array(arr.map!(b => array(b[].map!(c =>

Re: confused with data types

double[][] skalar_m_2d(double[][] arr, double skalar) { import std.algorithm; // return arr.map(a=> a[] *= skalar).array; arr.each!((ref a) => a[] *= skalar)); return arr; }

Re: is this a bug with writeln / std.algorithm.remove?

On Friday, 16 February 2018 at 13:57:07 UTC, Steven Schveighoffer wrote: You have a pretty good minimal test, put that in bugzilla along with the forum thread link and all the info we know. Mark it as a dmd bug, regression, along with the version where it regressed (2.076.1), and I would tag

Re: is this a bug with writeln / std.algorithm.remove?

On Friday, 16 February 2018 at 13:28:59 UTC, Steven Schveighoffer wrote: Strictly speaking, this is not necessarily proof that it's in phobos, there could have been changes elsewhere that cause one of the conditions to fail. However, testing this out, I found something very weird. If you

Re: is this a bug with writeln / std.algorithm.remove?

On Friday, 16 February 2018 at 11:45:21 UTC, arturg wrote: this code fails to compile: void delegate(void*) dg; void delegate(void*)[] dgs = [dg, dg, dg]; dgs.writeln; dgs.remove(1).writeln(); if you comment out dgs.writeln; it works as expected, it works if you use other types

is this a bug with writeln / std.algorithm.remove?

this code fails to compile: void delegate(void*) dg; void delegate(void*)[] dgs = [dg, dg, dg]; dgs.writeln; dgs.remove(1).writeln(); if you comment out dgs.writeln; it works as expected, it works if you use other types then void*: void delegate(int*) dg; void

Re: Dscanner - DCD - Dfix ... Editor support or the lack of it.

On Sunday, 28 January 2018 at 17:51:19 UTC, Jonathan M Davis wrote: Hmm. Thanks. I'll have to check that out. I haven't done anything with folds in ages. Fortunately, I don't have to do anything with python right now though. The main reason that I used it before was so that I could have

Re: Dscanner - DCD - Dfix ... Editor support or the lack of it.

On Sunday, 28 January 2018 at 16:02:36 UTC, Jonathan M Davis wrote: Erm, you do realize that Vim has built-in commands for navigating nested brackets and parentheses, right? And automatic bracket closing is just a macro away. You don't even need a plugin for that. LOL. One of the reasons

Re: Struct initialization syntax

On Wednesday, 17 January 2018 at 17:37:07 UTC, H. S. Teoh wrote: On Wed, Jan 17, 2018 at 05:31:03PM +, Azi Hassan via Digitalmars-d-learn wrote: The D tour for structs uses a syntax similar to that of C++ in order to initialize a Person struct : Person p(30, 180). Is this syntax supported

Re: Detect if variable defined

On Friday, 29 September 2017 at 18:03:52 UTC, Joseph wrote: static if () { enum x; } static if (isDefined!x) { } What's the correct way to check if a variable has been defined? (note x may or may not be defined above. I need to know if it is) import std.traits; static if(hasMember!(T,

Re: no print function output do while

On Thursday, 28 September 2017 at 20:17:24 UTC, Ali Çehreli wrote: On 09/28/2017 12:18 PM, dark777 wrote: On Thursday, 28 September 2017 at 18:46:56 UTC, Ali Çehreli wrote: On 09/28/2017 08:13 AM, dark777 wrote: no print function output do while in my program after entering the data and

Re: Base class' constructor is not implicitly inherited for immutable classes. A bug or a feature?

On Wednesday, 19 July 2017 at 16:00:56 UTC, Piotr Mitana wrote: Hello, I have this code: immutable class Base { this() {} } immutable class Derived : Base {} void main() { new immutable Derived(); } I'd like class Derived to automatically inherit the default constructor from

Re: Project Highlight: Derelict

On Monday, 26 June 2017 at 14:30:13 UTC, Mike Parker wrote: I've just published a wall of text about Derelict. I don't think I've ever written so much about it in one sitting, so it was a fun post to write. As well as (the reminder of how fast time is slipping away aside) a nice walk down

Re: Generic operator overloading for immutable types?

On Monday, 12 June 2017 at 19:51:37 UTC, Gary Willoughby wrote: I don't know how H. S. Teoh managed to answer 'before' I posted but thanks guys! :) might be a bug, happened here http://forum.dlang.org/post/ohbr5l$2mng$1...@digitalmars.com also.

Re: new contract syntax DIP

On Tuesday, 23 May 2017 at 17:28:21 UTC, MysticZach wrote: I made a pull request for a new DIP dealing with contract syntax: https://github.com/dlang/DIPs/pull/66 I write the DIP in response to the discussions for DIP 1003: http://forum.dlang.org/thread/wcqebjzdjxldeywlx...@forum.dlang.org

Re: Problem with using readln.

On Sunday, 30 April 2017 at 05:53:09 UTC, Andrew Edwards wrote: string line; parse!int((line = readln)).writeln; is there a reason you mix normal call and ufc or just some style? you can do this and remove some () (line = readln).parse!int.writeln;

Re: DIP 1005 - Preliminary Review Round 1

On Sunday, 23 April 2017 at 12:03:47 UTC, Andrei Alexandrescu wrote: On 4/22/17 4:52 PM, Joakim wrote: On Saturday, 22 April 2017 at 11:54:08 UTC, Mike Parker wrote: DIP 1005 is titled "Dependency-Carrying Declarations". https://github.com/dlang/DIPs/blob/master/DIPs/DIP1005.md All

Re: DIP10005: Dependency-Carrying Declarations is now available for community feedback

On Friday, 30 December 2016 at 23:49:23 UTC, Andrei Alexandrescu wrote: The main win, which indeed is not emphasized enough, is better encapsulation. Walter pointed that out, and I will redo the DIP to put that front and center. Maybe i can provide an example where i think DCD's would be

Re: DIP10005: Dependency-Carrying Declarations is now available for community feedback

On Thursday, 15 December 2016 at 19:52:50 UTC, Andrei Alexandrescu wrote: On 12/15/2016 02:22 PM, Timothee Cour via Digitalmars-d wrote: Some more details on my proposa based on UDA: ... I now understand the idea, thank you. My question is, doesn't this take things too far? Earlier I

Re: DIP10005: Dependency-Carrying Declarations is now available for community feedback

On Wednesday, 14 December 2016 at 22:56:54 UTC, Andrei Alexandrescu wrote: The acceptability of the proposal decays exponentially with its deviation from existing import syntax. -- Andrei sorry, i missed the import keyword :/ T1 fun(T1, T2)(T1 t1, T2 t2) import { version(A) {

Re: DIP10005: Dependency-Carrying Declarations is now available for community feedback

On Wednesday, 14 December 2016 at 19:39:55 UTC, Andrei Alexandrescu wrote: On 12/14/2016 02:04 PM, Meta wrote: On Wednesday, 14 December 2016 at 17:32:10 UTC, H. S. Teoh wrote: What about: /* Showing full declaration just for context */ bool myFunc(R1, R2)(R1 r1, R2 r2) import {

Re: @property

My issue isn't about @property, it just shows 3 cases where i think that dmd is missing a check for alias this. Even if D didnt had @property or parentesis less function call, due to alias opCall this it should be possible to call opCall without parentesis.

Re: @property

On Thursday, 8 December 2016 at 22:46:32 UTC, Jonathan M Davis wrote: On Thursday, December 08, 2016 22:11:22 ArturG via Digitalmars-d-learn wrote: On Thursday, 8 December 2016 at 16:54:57 UTC, Adam D. Ruppe wrote: > On Thursday, 8 December 2016 at 16:53:13 UTC, Satoshi wrote: >> is

Re: @property

On Thursday, 8 December 2016 at 16:54:57 UTC, Adam D. Ruppe wrote: On Thursday, 8 December 2016 at 16:53:13 UTC, Satoshi wrote: is there any advantage of marking function as @property?? Not really. I think it just changes the meaning of typeof(thatfunc) but otherwise it does nothing.

wrong result from ParameterStorageClassTuple?

alias PSC = ParameterStorageClass; alias PSCT = ParameterStorageClassTuple; void fun1(return ref int){} void fun2(return out int){} PSCT!fun1 == (PSC.return_ | PSC.ref_) // false PSCT!fun2 == (PSC.return_ | PSC.out_) // false PSCT!fun1 == PSC.return_ // true PSCT!fun2 == PSC.return_ // true

Re: @property get/set or public varaible?

On Sunday, 4 December 2016 at 20:44:05 UTC, Jonathan M Davis wrote: On Sunday, December 04, 2016 15:30:22 vladdeSV via Digitalmars-d-learn wrote: Hello! I have a question not directly related to D as it is with coding standards. My issue at hand is if I have one variable for a class, which

Is there some trait like getOverloads that works with mixin templates?

a simple example: mixin template v1() { void foo(){} } mixin template v2() { void foo(int){} } class Test { mixin v1; mixin v2; } void main() { __traits(getOverloads, Test, "foo").length.writeln; // 0 } i know you can use alias to manually make them visible for

Re: If Statement with Declaration

On Thursday, 3 November 2016 at 22:29:34 UTC, Jerry wrote: So I was thinking of a way of extending if statements that have declarations. The following being as example of the current use of if statements with declarations: if(int* weDontPollute = someFunc()) { // use

Re: Construct D Arrray with explicit capacity

On Sunday, 30 October 2016 at 18:10:09 UTC, Nordlöw wrote: Is there a recommended way to create a builtin D array with a given capacity? I'm aware of the `.capacity` property. Is it ok to mutate it? you cant mutate capacity directly because its only a getter but you could use

Re: Pattern matching in D?

On Friday, 21 October 2016 at 02:40:45 UTC, Stefan Koch wrote: On Friday, 21 October 2016 at 02:16:44 UTC, Chris M. wrote: So I know you can do some pattern matching with templates in D, but has there been any discussion about implementing it as a language feature, maybe something similar to

Re: TryElseExpression DIP

On Monday, 5 September 2016 at 18:07:52 UTC, pineapple wrote: It works like this: try: do_something() except Exception as e: pass # Runs when an error inheriting from Exception was raised else: pass # Runs when no error was raised finally: pass

Re: mixin template hide

On Sunday, 24 July 2016 at 18:38:53 UTC, Eppason wrote: The obvious solution is to refactor Bar, but in the real world, it is much harder and life would be much easier if I could remove foo from exists inside S. At worse, if Bar did depend on foo, I would simply get errors about missing

Re: Overloads

On Sunday, 26 June 2016 at 11:23:14 UTC, Márcio Martins wrote: Consider this snippet: struct X { int foo(Args...)(Args args) if (Args.length > 1) { return Args.length; } int foo() { return 0; } int foo(int y) { return 1; } alias Name = string; int field_; } void

named args

http://melpon.org/wandbox/permlink/u8lpOZ9owC7QXfa3 hi, that code is based on ideas and code from this[1] thread. some examples: // named and in order args!(fun, a=>6, b=>65, s=>"test", f=>1.4); // named and out of order args!(fun, b=>65, f=>1.4, s=>"test", a=>6); // unnamed and in

Re: foo => "bar" key/value literals in D!

On Saturday, 11 June 2016 at 15:46:59 UTC, Vladimir Panteleev wrote: Taking an address creates a function pointer, which loses the argument names. (Doesn't it?) unfortunatly yes, but it works as a struct or class initializer https://dpaste.dzfl.pl/6aad852aea90

Re: Monads in D

On Saturday, 11 June 2016 at 14:26:20 UTC, Atila Neves wrote: Why? Because I could, I don't plan on using this for anything serious. I think "with" is my favourite D feature right now. I also wrote the Writer and State monads (not that D needs them): https://github.com/atilaneves/felix

Re: foo => "bar" key/value literals in D!

On Saturday, 11 June 2016 at 09:07:43 UTC, Andrei Alexandrescu wrote: No, both are nice to have. If one name is needed for both, "args" is indeed a good commonality. "Invoke function f with these args" and "Construct an object of type T with these args". The problem is it's not very

Re: stretto...@tutanota.com

you could also use a simple wrapped cast Ret castTo(Ret, T)(T t) if(is(T == class)) { return cast(Ret) t; } then do foo.stuff[0].castTo!Dong.x.writeln; and if you want to guard the access you could try foo.stuff[0].castTo!Dong.cc!((d){d.x = 5;}); cc is an alias for checkCall which is a

Re: isCallable and templates

On Friday, 10 June 2016 at 17:32:03 UTC, Steven Schveighoffer wrote: Consider: import std.traits; class Foo { void bar() {} void baz()() {} } This works: static assert(isCallable!(Foo.bar)); This does not: static assert(isCallable!(Foo.baz)); However, clearly I can call baz due to

Formated string with assert inside template constraints?

is it supposed to work? normally it works e.g. assert(0, "some\nstring"); prints: some string but if you do it inside a template constraint like this: void someTemp(T)(T t) if(isCallable!T.call!((b){assert(b, "some\nstring");})) { } it prints: some\x0astring

chainable scopes

this is a library implementation based on the with expression[1] idea i posted a while ago and is kinda related to the ?. operator. as we cant fully implement the above idea as a library i tried to do what's possible which are basically chainable scopes[2]. implemented as 2 templates:

Re: Why do some T.init evaluate to true while others to false?

On Friday, 27 May 2016 at 14:48:59 UTC, Adam D. Ruppe wrote: On Friday, 27 May 2016 at 14:43:47 UTC, ArturG wrote: if(value is typeof(value).init) ... that still requiers a special case for floating points, arrays and optionally empty string literals. Have you tried? That should work

Re: Why do some T.init evaluate to true while others to false?

On Friday, 27 May 2016 at 18:03:23 UTC, Steven Schveighoffer wrote: I didn't change the default. The default is to pick the first member and use that as the init value. I may not have even considered what foo.init might be when I was creating my enum. -Steve by default i ment this enum

Re: Why do some T.init evaluate to true while others to false?

On Friday, 27 May 2016 at 16:56:21 UTC, Steven Schveighoffer wrote: Why are you expecting it to be? Won't work for enums with first elements that are non-zero either: enum foo : int { bar = 1; } foo f; if(f) writeln("this will output too"); -Steve but by default it works you just

Re: Why do some T.init evaluate to true while others to false?

On Friday, 27 May 2016 at 15:24:18 UTC, Adam D. Ruppe wrote: On Friday, 27 May 2016 at 15:19:50 UTC, ArturG wrote: yes but i have to check for that when some one does Why? This is no different than if they set any of the other four billion possible values. What do you mean? operation on

Re: Why do some T.init evaluate to true while others to false?

On Friday, 27 May 2016 at 15:07:50 UTC, Adam D. Ruppe wrote: On Friday, 27 May 2016 at 14:56:28 UTC, ArturG wrote: float f; if(f is float.init) "float init".writeln; f = float.nan; if(f is float.init) "float nan".writeln; You changed it to a value that isn't float.init, so of

Re: Why do some T.init evaluate to true while others to false?

On Friday, 27 May 2016 at 14:48:59 UTC, Adam D. Ruppe wrote: On Friday, 27 May 2016 at 14:43:47 UTC, ArturG wrote: if(value is typeof(value).init) ... that still requiers a special case for floating points, arrays and optionally empty string literals. Have you tried? That should work

Re: Why do some T.init evaluate to true while others to false?

On Friday, 27 May 2016 at 09:25:55 UTC, Marc Schütz wrote: On Thursday, 26 May 2016 at 16:45:22 UTC, ArturG wrote: im just playing with this template[1] is there anything else i missed? (if you dont mind) it basically treats any T.init as false and skips the function/delegate and just returns

Re: Why do some T.init evaluate to true while others to false?

On Thursday, 26 May 2016 at 15:51:39 UTC, Basile B. wrote: Oh, I'm so sorry ! I totally missed the point of the Q. float.nan is not a "unique" value. Several values verify "nan" (Look at std.math.isNan). So I suppose it's simpler to test for nullity. Though with the sign there's also two

Re: Why do some T.init evaluate to true while others to false?

On Thursday, 26 May 2016 at 15:38:55 UTC, Basile B. wrote: because nan is not 0 and that the shortcut for float is if (fpValue) <=> if (fpValue != 0) if (!fpValue)<=> if (fpValue == 0) There's no relation between the initializer and the shortcut. It's not because for some values the

Re: Why do some T.init evaluate to true while others to false?

On Thursday, 26 May 2016 at 15:29:52 UTC, Basile B. wrote: float.init is not equal to 0.0f. In D FP points values are initialized to nan (not a number). By the way for strings it works, it's like the array case I described in the first answer). yes i guess i tested all/most types and

Re: Why do some T.init evaluate to true while others to false?

On Thursday, 26 May 2016 at 15:25:26 UTC, ag0aep6g wrote: On 05/26/2016 04:03 PM, ArturG wrote: for example: if(any floatingpoint.init) will be true if(any char.init) also true if("") also true while others are false e.g. string s; if(s) will be false all others are also false or did i miss

Re: Why do some T.init evaluate to true while others to false?

On Thursday, 26 May 2016 at 15:15:57 UTC, Basile B. wrote: On Thursday, 26 May 2016 at 15:14:21 UTC, Basile B. wrote: On Thursday, 26 May 2016 at 15:11:50 UTC, Basile B. wrote: On Thursday, 26 May 2016 at 14:03:16 UTC, ArturG wrote: [...] [...] - integral(*): if (i) <=> if (i > 0) I

Re: Effect of declaring a class immutable ?

On Thursday, 26 May 2016 at 14:12:23 UTC, chmike wrote: I couldn't find any information about this on the dlang web site. What is the effect adding the immutable attribute to a class like this immutable class MyClass { ... } The compiler doesn't complain. Will it add the immutable

Why do some T.init evaluate to true while others to false?

for example: if(any floatingpoint.init) will be true if(any char.init) also true if("") also true while others are false e.g. string s; if(s) will be false all others are also false or did i miss any?

Re: with and checked with expression?

On Wednesday, 25 May 2016 at 00:36:04 UTC, Seb wrote: On Tuesday, 24 May 2016 at 19:03:11 UTC, ArturG wrote: would something like this be usefull? A general word of advice - try to keep your post short & concise. It is more likely to get replies then. Yes i might have used to many

with and checked with expression?

ive read some discussions about some library solution for the ?. operator, has there been anything added to phobos? wouldnt a checked with expression be a more general/longer form of the ?. operator? A with expression not only allows you to do unchecked/checked access to members but to any

Re: Usage of custom class with JSONValue

On Thursday, 24 March 2016 at 08:24:46 UTC, Edwin van Leeuwen wrote: JSONValue only works with the build in types, not with user defined types. Either you define a specific function for the class that returns a JSONValue. Easiest way to do that would be to build an associative array with

Re: Named arguments via struct initialization in functions

hi, has the UDA syntax been proposed already? void fun(int foo, int bar, int bazDaz = 0){} fun(10, 30, 50); // normal fun(10, 30); normal with default fun(10, 30, @bazDaz 50); // mixed fun(@bazDaz 50, 10, 30) // mixed and reordered fun(@bar 30, 10); // mixed, reordered and default fun(@foo

Re: DIP 88: Simple form of named parameters

On Monday, 25 January 2016 at 08:55:55 UTC, Jacob Carlborg wrote: On 2016-01-24 19:23, Chris Wright wrote: It shouldn't. However, it is another way to pass function arguments, so for thoroughness it would be better to mention it. Added an example. Is this what you intended? If so, please

Re: DIP 88: Simple form of named parameters

On Monday, 25 January 2016 at 13:40:18 UTC, HaraldZealot wrote: On Saturday, 23 January 2016 at 14:19:03 UTC, Jacob Carlborg wrote: This is mostly to prevent ugly hacks like Flag [1]. http://wiki.dlang.org/DIP88 [1] https://dlang.org/phobos/std_typecons.html#.Flag Why not simply allow

Re: DIP 88: Simple form of named parameters

On Monday, 25 January 2016 at 16:50:49 UTC, HaraldZealot wrote: On Monday, 25 January 2016 at 14:35:09 UTC, arturg wrote: On Monday, 25 January 2016 at 13:40:18 UTC, HaraldZealot wrote: the equal sign cant be used because D behaves like this int width, height; foo(width = 5, height = 10); //

Re: DIP 88: Simple form of named parameters

On Monday, 25 January 2016 at 16:17:27 UTC, Chris Wright wrote: It's a comment that the compiler verifies. You could argue that the bulk of the type system is comments that the compiler verifies. named arguments solve this problem void foo(int a = 4, int b = 10, int c = 3) {} foo(c : 5);

Re: why the sort result is different with C#

On Friday, 22 January 2016 at 06:53:29 UTC, mzf wrote: D code: auto arr = ["b1=1", "b=2","a1=1", "a=2"]; writeln(arr.sort()); output:["a1=1", "a=2", "b1=1", "b=2"] C# code: var arr = new string[]{ "b1=1", "b=2", "a1=1", "a=2" }; Array.Sort(arr); output:["a=2","a1=1","b=2","b1=1"] auto