• Matthias Walter (12/12) Dec 11 2010 Hi all,
• Craig Black (14/14) Dec 11 2010 Not sure if this is the de facto answer, but I found this one from back ...
• Dmitry Olshansky (7/19) Dec 12 2010 There is actually almost forgotten function in std.functional -
• Matthias Walter (2/23) Dec 12 2010 Ah, thank you very much! That looks like what I was looking for.

Matthias Walter <xammy xammy.homelinux.net> writes:

Hi all,

there was a discussion in 2006 but w/o a result, and I didn't find any
bugs about implicitely casting functions to delegates. It seems to be
impossible as long as function-pointer calls work differently than
delegate calls in the ABI. Will this at some point be fixed?

If not, is there a conversion function in phobos (I didn't find one)? I
played a bit and found that this one might work:

R delegate(A) funcionToDelegate (R, A...) (R function(A) func)
{
  return (A a){ return func(a); };
}

Matthias

"Craig Black" <craigblack2 cox.net> writes:

Not sure if this is the de facto answer, but I found this one from back in 
the day.

R delegate(T) toDg(R, T...)(R function(T) fp) {
    struct dg {
        R opCall(T t) {
            return (cast(R function(T)) this) (t);
        }
    }
    R delegate(T) t;
    t.ptr = fp;
    t.funcptr = &dg.opCall;
    return t;
 }

-Craig 

Dmitry Olshansky <dmitry.olsh gmail.com> writes:

On 12.12.2010 7:25, Matthias Walter wrote:
 Hi all,

 there was a discussion in 2006 but w/o a result, and I didn't find any
 bugs about implicitely casting functions to delegates. It seems to be
 impossible as long as function-pointer calls work differently than
 delegate calls in the ABI. Will this at some point be fixed?

 If not, is there a conversion function in phobos (I didn't find one)? I
 played a bit and found that this one might work:

 R delegate(A) funcionToDelegate (R, A...) (R function(A) func)
 {
    return (A a){ return func(a); };
 }

 Matthias

There is actually almost forgotten function in std.functional - 
toDelegate, which does it in the most general way, functional objects 
covered.
Sadly enough it's not listed in docs, because of the auto return.

-- 
Dmitry Olshansky

Matthias Walter <xammy xammy.homelinux.net> writes:

On 12/12/2010 06:15 AM, Dmitry Olshansky wrote:
 On 12.12.2010 7:25, Matthias Walter wrote:
 Hi all,

 there was a discussion in 2006 but w/o a result, and I didn't find any
 bugs about implicitely casting functions to delegates. It seems to be
 impossible as long as function-pointer calls work differently than
 delegate calls in the ABI. Will this at some point be fixed?

 If not, is there a conversion function in phobos (I didn't find one)? I
 played a bit and found that this one might work:

 R delegate(A) funcionToDelegate (R, A...) (R function(A) func)
 {
    return (A a){ return func(a); };
 }

 Matthias

 There is actually almost forgotten function in std.functional -
 toDelegate, which does it in the most general way, functional objects
 covered.
 Sadly enough it's not listed in docs, because of the auto return.

Ah, thank you very much! That looks like what I was looking for.