• Marcel (10/10) Feb 18 2020 Hello!
• Dennis (20/23) Feb 20 2020 The best I can think of is:
• Marcel (7/30) Feb 21 2020 That will do, thank you!
• Steven Schveighoffer (9/23) Feb 20 2020 Since D conditional compilation must always be a valid declaration or
• Marcel (3/26) Feb 21 2020 That's a shame...

Marcel <marcelpi97 gmail.com> writes:

Hello!

Say I have a struct where every member function can either be 
static or not depending on a template parameter. Is there a 
simple way to do this? Like, for example:

struct Foo(Condition)
{
    static if (Condition) static:

    void Bar() {}
    void Baz() {}

}

Dennis <dkorpel gmail.com> writes:

On Tuesday, 18 February 2020 at 17:11:55 UTC, Marcel wrote:
 Say I have a struct where every member function can either be 
 static or not depending on a template parameter. Is there a 
 simple way to do this?

The best I can think of is:

```
mixin template maybeStatic() {
     void foo() {
         // implementation
     }
}

struct S(bool condition) {
     static if (condition) {
         static {
             mixin maybeStatic;
         }
     } else {
         mixin maybeStatic;
     }
}
```

What do you need this for? It seems like an unusual situation to 
me.

Marcel <marcelpi97 gmail.com> writes:

On Thursday, 20 February 2020 at 17:41:54 UTC, Dennis wrote:
 On Tuesday, 18 February 2020 at 17:11:55 UTC, Marcel wrote:
 Say I have a struct where every member function can either be 
 static or not depending on a template parameter. Is there a 
 simple way to do this?

 The best I can think of is:

 ```
 mixin template maybeStatic() {
     void foo() {
         // implementation
     }
 }

 struct S(bool condition) {
     static if (condition) {
         static {
             mixin maybeStatic;
         }
     } else {
         mixin maybeStatic;
     }
 }
 ```

 What do you need this for? It seems like an unusual situation 
 to me.

That will do, thank you!
I'm making an allocator library similar to what Andrei 
Alexandrescu presented at CppCon. Since some allocators may not 
have state, those that inherit* from them may need to have every 
member function marked as static.

*I'm using mixins instead of inheritance.

Steven Schveighoffer <schveiguy gmail.com> writes:

On 2/18/20 12:11 PM, Marcel wrote:
 Hello!
 
 Say I have a struct where every member function can either be static or 
 not depending on a template parameter. Is there a simple way to do this? 
 Like, for example:
 
 struct Foo(Condition)
 {
     static if (Condition) static:
 
     void Bar() {}
     void Baz() {}
 
 }

Since D conditional compilation must always be a valid declaration or 
statement, you cannot do something like this.

The closest you can do is to use mixins, which means you have to write 
everything inside strings.

It has been proposed quite a few times to have a way to enable/disable 
attributes based on a compile-time boolean. But it's never come close to 
getting included.

-Steve

Marcel <marcelpi97 gmail.com> writes:

On Friday, 21 February 2020 at 01:41:21 UTC, Steven Schveighoffer 
wrote:
 On 2/18/20 12:11 PM, Marcel wrote:
 Hello!
 
 Say I have a struct where every member function can either be 
 static or not depending on a template parameter. Is there a 
 simple way to do this? Like, for example:
 
 struct Foo(Condition)
 {
     static if (Condition) static:
 
     void Bar() {}
     void Baz() {}
 
 }

 Since D conditional compilation must always be a valid 
 declaration or statement, you cannot do something like this.

 The closest you can do is to use mixins, which means you have 
 to write everything inside strings.

 It has been proposed quite a few times to have a way to 
 enable/disable attributes based on a compile-time boolean. But 
 it's never come close to getting included.

 -Steve

That's a shame...