Re: move an argument tuple

[Atila Neves via Digitalmars-d]

On Thursday, 7 December 2017 at 08:19:25 UTC, Shachar Shemesh 
wrote:
Hi everybody,

I'm trying to have a templated function like so:
    void func(alias F)(Parameters!F args) {

At some point in func, I want to call F with args:
   F(args);

This does not work if one of args is a struct with copying 
disabled. That's fine. What I'd like to do is to move it into F:
   F( move(args) );

Except that only works if args.length==1. If args.length==2, it 
thinks I'm calling the move overload that moves from the first 
argument to the second, and then it complains that F cannot be 
called with void argument.

Things that also don't work:
  F( moveAll(args) );
That one accepts two ranges and expects to copy between them.

I guess I can put up a mixin that expands to:
  F( move(args[0]), move(args[1]) );

I'd really like a cleaner solution if one is possible.

Thanks,
Shachar

import std.traits: Parameters;
import std.stdio: writeln;
import std.functional: forward;

struct Foo {
    int i;
    @disable this(this);
}

auto add(Foo f, Foo g) {
    return f.i + g.i;
}

void main() {
    func!add(Foo(1), Foo(2));
}

void func(alias F)(Parameters!F args) {
    writeln(F(forward!args));
}