Re: Purpose of template DECLARE_HANDLE in druntime
On Friday, 1 February 2019 at 08:12:23 UTC, Andre Pany wrote:
On Friday, 1 February 2019 at 07:35:34 UTC, Kagamin wrote:
It's a strong typed handle, in C it's declared as
#ifdef STRICT
typedef void *HANDLE;
#if 0 && (_MSC_VER > 1000)
#define DECLARE_HANDLE(name) struct name##__; typedef struct
name##__ *name
#else
#define DECLARE_HANDLE(name) struct name##__{int unused;};
typedef struct name##__ *name
#endif
#else
typedef PVOID HANDLE;
#define DECLARE_HANDLE(name) typedef HANDLE name
#endif
Thanks for all answers.
I understand, there was a reason in the past, but now
it is a superfluous construct.
I will create an issue and after that checks whether I can
create a pull request.
Kind regards
André
Issue created
https://issues.dlang.org/show_bug.cgi?id=19702
Re: Purpose of template DECLARE_HANDLE in druntime
On Friday, 1 February 2019 at 07:35:34 UTC, Kagamin wrote:
It's a strong typed handle, in C it's declared as
#ifdef STRICT
typedef void *HANDLE;
#if 0 && (_MSC_VER > 1000)
#define DECLARE_HANDLE(name) struct name##__; typedef struct
name##__ *name
#else
#define DECLARE_HANDLE(name) struct name##__{int unused;};
typedef struct name##__ *name
#endif
#else
typedef PVOID HANDLE;
#define DECLARE_HANDLE(name) typedef HANDLE name
#endif
Thanks for all answers.
I understand, there was a reason in the past, but now
it is a superfluous construct.
I will create an issue and after that checks whether I can
create a pull request.
Kind regards
André
Re: Purpose of template DECLARE_HANDLE in druntime
It's a strong typed handle, in C it's declared as
#ifdef STRICT
typedef void *HANDLE;
#if 0 && (_MSC_VER > 1000)
#define DECLARE_HANDLE(name) struct name##__; typedef struct
name##__ *name
#else
#define DECLARE_HANDLE(name) struct name##__{int unused;};
typedef struct name##__ *name
#endif
#else
typedef PVOID HANDLE;
#define DECLARE_HANDLE(name) typedef HANDLE name
#endif
Re: Purpose of template DECLARE_HANDLE in druntime
On Thursday, 31 January 2019 at 20:51:37 UTC, Andre Pany wrote:
I noticed in druntime this template is used often:
package template DECLARE_HANDLE(string name, base = HANDLE) {
mixin ("alias " ~ base.stringof ~ " " ~ name ~ ";");
If my memory is correct, it is actually for old D compatibility.
It used to do `version(D1) typedef, else alias`.
You can see in the code right above it that there is a commented
struct and a usage of library Typedef too. A little bit further
up is a comment about Typedef being because of new versions of D
deprecating the keyword.
Old typedef fit the bill quite nicely, but it got deprecated and
removed from the language. These headers used to be usable for
various versions of D, and the mixin string lets you use keywords
that no longer exist and centralize it a bit.
I don't think it tries to support old D any more, but I just
don't believe anyone has wanted to change it. Programmers don't
like to remove clever indirection tricks after writing them...
what if you think of some better way to do it later?!
Re: Purpose of template DECLARE_HANDLE in druntime
On Thursday, 31 January 2019 at 20:51:37 UTC, Andre Pany wrote:
Hi,
I noticed in druntime this template is used often:
package template DECLARE_HANDLE(string name, base = HANDLE) {
mixin ("alias " ~ base.stringof ~ " " ~ name ~ ";");
The disadvantage is, IDEs like IntelliJ are not able to find
the symbols using this template e.g.
mixin DECLARE_HANDLE!("SC_HANDLE");
What is the benefit of this template?
Why can't we just use
alias HANDLE SC_HANDLE;
Kind regards
Andre
Have you tried changing it to alias and check whether the
testsuite still passes?
Druntime is a bit old, so I wouldn't be too surprised if this is
an old relict.
Re: Purpose of template DECLARE_HANDLE in druntime
On 1/31/19 3:51 PM, Andre Pany wrote:
Hi,
I noticed in druntime this template is used often:
package template DECLARE_HANDLE(string name, base = HANDLE) {
mixin ("alias " ~ base.stringof ~ " " ~ name ~ ";");
The disadvantage is, IDEs like IntelliJ are not able to find the symbols
using this template e.g.
mixin DECLARE_HANDLE!("SC_HANDLE");
What is the benefit of this template?
Why can't we just use
alias HANDLE SC_HANDLE;
Most likely it's a direct translation from a C preprocessor macro.
-Steve
Purpose of template DECLARE_HANDLE in druntime
Hi,
I noticed in druntime this template is used often:
package template DECLARE_HANDLE(string name, base = HANDLE) {
mixin ("alias " ~ base.stringof ~ " " ~ name ~ ";");
The disadvantage is, IDEs like IntelliJ are not able to find the
symbols using this template e.g.
mixin DECLARE_HANDLE!("SC_HANDLE");
What is the benefit of this template?
Why can't we just use
alias HANDLE SC_HANDLE;
Kind regards
Andre
