Re: meaning of "auto ref const"?

On Tuesday, 20 December 2016 at 20:08:32 UTC, Ali Çehreli wrote: If the purpose is optimization, the good news are Yes it is :) * Classes are already reference types so there is no lvalue or rvalue reference distinction there Ok, this one is quite intuitive. import std.stdio; ...

Re: meaning of "auto ref const"?

On Tuesday, 20 December 2016 at 19:24:32 UTC, Ali Çehreli wrote: As a general rule, 'auto ref' should probably be const. If the purpose of 'ref' is so that the argument would be mutated, then allowing a copy of an rvalue to this function could very well be a bug: struct S { int i; }

Re: meaning of "auto ref const"?

On Sunday, 18 December 2016 at 14:32:08 UTC, kinke wrote: TypeInfo_Struct apparently requires (or used to require) an `int opCmp(ref const T rhs)` overload, i.e., a version taking the rhs lvalue argument by reference (see https://dlang.org/spec/operatoroverloading.html#compare). Note that

Re: meaning of "auto ref const"?

On Sunday, 18 December 2016 at 14:25:04 UTC, Basile B. wrote: ... As you can see, auto ref is more flexible with the parameter. This make sense for templated functions. Thank you for your detailed answer, things are perfectly clear now. Also sorry for the doc linksI should have found it

meaning of "auto ref const"?

Reading std/bigint.d code: https://github.com/dlang/phobos/blob/00c1cc3b0d354363793c8b419ce84da722578138/std/bigint.d#L589 I have seen this: bool opEquals()(auto ref const BigInt y) const pure @nogc { return sign == y.sign && y.data == data; } my problem is that I do not understand the

Re: [Semi-OT] I don't want to leave this language!

On Wednesday, 7 December 2016 at 16:15:32 UTC, Chris wrote: I don't understand this discussion at all. Why not have both? I don't need bare metal stuff at the moment but I might one day, and I perfectly understand that people may need it. At the same time, there are people who are happy

Re: [Semi-OT] I don't want to leave this language!

On Wednesday, 7 December 2016 at 11:48:32 UTC, bachmeier wrote: I write D code all the time for my research. I want to write correct code quickly. My time is too valuable to spend weeks writing code to cut the running time by a few minutes. That might be fun for some people, but it doesn't

Re: [Semi-OT] I don't want to leave this language!

On Tuesday, 6 December 2016 at 17:00:35 UTC, Jonathan M Davis wrote: So, while there are certainly folks who would prefer using D as a better C without druntime or Phobos, I think that you're seriously overestimating how many folks would be interested in that. Certainly, all of the C++

Re: fPIC Error

On Thursday, 3 November 2016 at 05:16:11 UTC, Dlang User wrote: I am running Debian Testing and I think I have run into the recent fPIC issue. This is the source code for the test project I am using: import std.stdio; void main() { writeln("Edit source/app.d to start your

A curated list of links related to D (github/awesome D)

Maybe interesting (hoping it is not too redundant with the links here) https://github.com/zhaopuming/awesome-d Vincent

Re: static array internal & dangling reference

On Monday, 14 November 2016 at 17:15:43 UTC, Steven Schveighoffer wrote: What has happened is that the stack allocated for f() (and since released) is still referenced by sb[]. In a weird way, since you haven't called any other functions, that data is still "valid"! Thank you for the

Re: static array internal & dangling reference

On Monday, 14 November 2016 at 06:10:38 UTC, Jonathan M Davis wrote: I would have hoped that it would have complained about the first one. I don't know why it isn't. It definitely results in having a pointer to memory that should no longer be referenced. Yes I would have hoped too, because

Re: static array internal & dangling reference

On Sunday, 13 November 2016 at 23:39:37 UTC, Steven Schveighoffer wrote: Note that he is declaring an int[10] inside the function and then returning it. The compiler must see that the int[10] will be returned, and so it reuses the pre-allocated buffer for returning as the same address to

Re: static array internal & dangling reference

On Saturday, 12 November 2016 at 11:03:31 UTC, Mike Parker wrote: Thank you very much for your clarifications & explanations, I am reassured to see that things work like in C. I will also look the links you provided, thank you again for your time. Vincent

Re: static array internal & dangling reference

Thank you for your answer cym13. I reproduced your result for: On Saturday, 12 November 2016 at 10:45:23 UTC, cym13 wrote: void f_test() { auto sb=f(); sb[2] = 100; writeln(sb[2]); // prints 100 int test[100]; writeln(sb[2]); // prints 0 } now I am convinced of the

static array internal & dangling reference

Hi all, Still learning... This time what surprised me is how static arrays work. I assume (is it true?) that for efficiency reason static size arrays like int[10] are on the stack and do not involve dynamic memory allocation: First surprise: it is possible to share a static array: void

Re: cross_module function overloading & alias & template: how to ?

On Thursday, 10 November 2016 at 20:12:10 UTC, Jonathan M Davis wrote: On Thursday, November 10, 2016 17:41:02 Picaud Vincent via Digitalmars-d- learn wrote: It is certainly a compiler problem: I used gdc -> compile error, but with dmd it compiles and runs fine. Full details in the git r

Re: cross_module function overloading & alias & template: how to ?

On Thursday, 10 November 2016 at 17:12:32 UTC, Jonathan M Davis wrote: On Thursday, November 10, 2016 15:46:11 Picaud Vincent via Digitalmars-d- learn wrote: [...] Honestly, I'm surprised that the compiler let you alias std.algorithm.comparison.min, because it's a templated function

cross_module function overloading & alias & template: how to ?

Hi All, In my adventure to learn a little bit of D coming from C++ I am now faced with the following problem: I have read about "cross-module overloading", §5.5.2 page 146 of Andrei Alexandrescu book. That makes sense to me and this is interesting. As a concrete example here the scenario:

Re: New to D and mimicking C++ : how to implement std::integral_constant<>?

Hi Basile, Thank you for your code, it allowed me to grasp a little bit more about how to do things in D. Vincent

Re: New to D and mimicking C++ : how to implement std::integral_constant<>?

On Monday, 7 November 2016 at 23:07:27 UTC, Picaud Vincent wrote: typo... auto capacity = max(0,(size_-1)*stride_+1); To be more correct I have something like: alias IntergralConstant!(int,0) Zero_c; alias IntergralConstant!(int,1) One_c; auto capacity =

Re: New to D and mimicking C++ : how to implement std::integral_constant<>?

On Monday, 7 November 2016 at 22:18:56 UTC, Jerry wrote: On Monday, 7 November 2016 at 21:37:50 UTC, Picaud Vincent wrote: static if ( isIntegralConstant!(typeof(required_capacity()) ) { } else { } } Premature post send by error sorry Well something like: static if (

Re: New to D and mimicking C++ : how to implement std::integral_constant<>?

On Monday, 7 November 2016 at 21:23:37 UTC, Picaud Vincent wrote: On Monday, 7 November 2016 at 18:59:24 UTC, Jerry wrote: On Monday, 7 November 2016 at 18:42:37 UTC, Picaud Vincent wrote: template isIntegralConstant(ANY) { enum bool

Re: New to D and mimicking C++ : how to implement std::integral_constant<>?

On Monday, 7 November 2016 at 18:59:24 UTC, Jerry wrote: On Monday, 7 November 2016 at 18:42:37 UTC, Picaud Vincent wrote: template isIntegralConstant(ANY) { enum bool isIntegralConstant=__traits(identifier,ANY)=="IntegralConstant"; } A bit more elegant way of doing that would be: enum

New to D and mimicking C++ : how to implement std::integral_constant<>?

Hi all, I have ~15y of C++ and now I want to test D, because it seems really intersting and "cleaner" than C++. As an exercice I m trying to implement something equivalent to the C++ std::integral_constant in D. In D: struct IntegralConstant(T, T VALUE) { ... } But I do not