Re: constructed variadic call
I don't think it's possible to call a vararg function whose number of arguments is only known at runtime, for the same reasons it is impossible in C [1]. Your switch statement is probably the best you can do, other than rewriting the API to not use varargs (which, depending on what the function is doing, I would recommend). You can possibly use string mixins or static foreach to avoid repeating the case clauses. [1] Populating a va_list: http://stackoverflow.com/questions/988290/populating-a-va-list That was fast :). The generation idea helps a little - thanks. It works though and I can't use va_list in this case. erik
Re: constructed variadic call
On Monday, 2 May 2016 at 18:22:52 UTC, Erik Smith wrote:
Is there way to construct an "argument pack" from a non-static
array (like the switch below)? I need to transport a variadic
call through a void*.
switch (a.length) {
case 1: foo(a[1]); break;
case 2: foo(a[1], a[2]); break;
case 3: foo(a[1], a[2], a[3]); break;
...
}
I don't think it's possible to call a vararg function whose
number of arguments is only known at runtime, for the same
reasons it is impossible in C [1].
Your switch statement is probably the best you can do, other than
rewriting the API to not use varargs (which, depending on what
the function is doing, I would recommend). You can possibly use
string mixins or static foreach to avoid repeating the case
clauses.
[1] Populating a va_list:
http://stackoverflow.com/questions/988290/populating-a-va-list
Re: constructed variadic call
On Monday, 2 May 2016 at 18:56:59 UTC, Stefan Koch wrote:
On Monday, 2 May 2016 at 18:22:52 UTC, Erik Smith wrote:
Is there way to construct an "argument pack" from a non-static
array (like the switch below)? I need to transport a variadic
call through a void*.
switch (a.length) {
case 1: foo(a[1]); break;
case 2: foo(a[1], a[2]); break;
case 3: foo(a[1], a[2], a[3]); break;
...
}
Yes there is.
Using a string mixin.
I'm not sure how to apply mixins here because they require
compile time evaluation and a.length is runtime. Ideas?
erik
Re: constructed variadic call
On Monday, 2 May 2016 at 18:22:52 UTC, Erik Smith wrote:
Is there way to construct an "argument pack" from a non-static
array (like the switch below)? I need to transport a variadic
call through a void*.
switch (a.length) {
case 1: foo(a[1]); break;
case 2: foo(a[1], a[2]); break;
case 3: foo(a[1], a[2], a[3]); break;
...
}
Yes there is.
Using a string mixin.
constructed variadic call
Is there way to construct an "argument pack" from a non-static
array (like the switch below)? I need to transport a variadic
call through a void*.
switch (a.length) {
case 1: foo(a[1]); break;
case 2: foo(a[1], a[2]); break;
case 3: foo(a[1], a[2], a[3]); break;
...
}
