Make toDelegate safe for function pointers

[Bolpat]

No description provided.

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Testing this PR locally

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dub run digger -- build "master + phobos#8769"

[dkorpel]

Why is there a new branch for function pointers, is the final else case obsolete now?

• $(LI Does not work with @safe functions.)

This line is no longer accurate now

[Bolpat]

Why is there a new branch for function pointers, is the final else case obsolete now?

Because toDelegate works with any callable, the else branch cannot be @safe in general. To be @safe for function pointers, toDelegate needed a specific branch (or it looked like the best solution to me).

[Bolpat]

• $(LI Does not work with @safe functions.)

This line is no longer accurate now

That should have been a review comment.

[dkorpel]

That should have been a review comment.

I can't comment on code not in the diff

[dkorpel]

Because toDelegate works with any callable

There's now branches for delegate, function, and opCall, what remaining cases does toDelegate support?

[dkorpel]

Ping @Bolpat

[dkorpel]

Ping @Bolpat

[Bolpat]

Sorry, I was absent for a while. I looked into the failed checks and didn’t understand what’s wrong.

Should I force-push?

[PetarKirov]

@Bolpat yes, please rebase & force-push.

[dkorpel]

Also, please answer #8769 (comment)

[0xEAB]

So, what did we expect the compiler to do that makes a delegate call to the resulting delegate a valid function call?

[0xEAB]

The way this current patch implements the delegate-to-function conversion by leaving the context pointer on the delegate default to null still won’t change that a delegate call makes a function receive a context-pointer parameter.

I’ve tried to visualize the issue:

import std.stdio;

void main() {
	auto fun = function (size_t a) {
		writeln("Fun: ", a);
	};
	auto del = delegate (size_t a) {
		writeln("Del: ", a);
	};

	auto ehm = function(size_t a, size_t b) {
		writeln("ehm: ", a);
		writeln("ehm: ", b);
	};

	void delegate(size_t) fake1;
	fake1.funcptr = fun;

	void delegate(size_t) fake2;
	fake2.ptr = cast(void*) 69;
	fake2.funcptr = cast(void function(size_t)) ehm;


	fun(7);
	del(7);
	fake1(7);
	fake2(7);
}

Fun: 7
Del: 7
Fun: 0
ehm: 69
ehm: 7

[LightBender]

Closed as superseded by: #10599