Re: How to use core.atomic.cas with (function) pointers?

[Kagamin via Digitalmars-d-learn]

I believe this is historical. It will fail because atomics are 
combinatorially parameterized because the compiler couldn't 
properly infer template arguments until recently (this also 
resulted in memory corruption in ldc fork of druntime). Now that 
the compiler was fixed, atomics can be fixed too and have single 
template parameter.

Re: How to use core.atomic.cas with (function) pointers?

[Nicholas Wilson via Digitalmars-d-learn]

On Tuesday, 22 January 2019 at 14:13:23 UTC, Johan Engelen wrote:

The following code compiles:
```
alias T = shared(int)*;

shared T a;
shared T b;
shared T c;

void foo() {
import core.atomic: cas;
cas(&a, b, c);
}
```

The type of T has to be a pointer to a shared int (you get a 
template match error for `cas` if `T = int*`), which is 
annoying but I kind-of understand.
However, change b to null (`cas(&a, null, c);`) and things no 
longer work: "Error: template `core.atomic.cas` cannot deduce 
function from argument types"


I have not succeeded to make things work with function pointers 
(neither with nor without `null` as second argument). What am I 
doing wrong if `alias T = void function();` ?


Thanks,
  Johan


You need to cast stuff (as seems to be the case with everything 
to do with shared, at least until/if Manu's proposal goes 
through):


alias T = void function();
alias S = shared(size_t*);
shared T a;
shared T b;
shared T c;

void foo() {
import core.atomic: cas;
cas(cast(S*)&a, cast(S)b, cast(S)c);
}

How to use core.atomic.cas with (function) pointers?

[Johan Engelen via Digitalmars-d-learn]

The following code compiles:
```
alias T = shared(int)*;

shared T a;
shared T b;
shared T c;

void foo() {
import core.atomic: cas;
cas(&a, b, c);
}
```

The type of T has to be a pointer to a shared int (you get a 
template match error for `cas` if `T = int*`), which is annoying 
but I kind-of understand.
However, change b to null (`cas(&a, null, c);`) and things no 
longer work: "Error: template `core.atomic.cas` cannot deduce 
function from argument types"


I have not succeeded to make things work with function pointers 
(neither with nor without `null` as second argument). What am I 
doing wrong if `alias T = void function();` ?


Thanks,
  Johan