fix Issue 13662: @safe pure nothrow @nogc findRoot

[9il]

Reason: allows findRoot be used in @safe @nogc nothrow code.

[MartinNowak]

Can you please file a bugzilla issue for the @safe @nogc nothrow thing.
Among other things this allows us to automatically mention this in the changelog.

[MartinNowak]

You should add an overload to make that work again or this change will break code.
Maybe it's possible to deprecate the overload at some point.

[9il]

I have no Idea how to make overload =(

This unittest was written by me for regression control (allow different R and T types in the same time). I think nobody use this style.

[MartinNowak]

Well just add a function with the old signature and forward it's implementation to the new find root.

[9il]

copy-past:

I have no Idea how to make overload =(

This unittest was written by me for regression control (allow different R and T types in the same time). I think nobody use this style.

[mihails-strasuns]

What is the problem with this one? Why it doesn't work anymore?

[mihails-strasuns]

I see, link to original question : #2639 (comment)

[mihails-strasuns]

I am actually not sure why compiler can't find matching overload here, looks unambiguous.

[MartinNowak]

The template signature changed, so we need to add an overload with the old signature.

[9il]

If I add an overload for old signature than findRoot won't be compiled in most cases because there will be 2 suitable templates .

[quickfur]

ping
Any updates based on comments?

[9il]

no idea =(

[9il]

I think we can push this commit as is or create something like findRootOld.

[MartinNowak]

Doesn't the default argument work here?
Maybe in combination with a default type for DT?

[9il]

I will try.

[9il]

Compatible for delegates only, but not for other callable entities (functions, structs, objects).

[MartinNowak]

So please add back the old signature as overload.

T findRoot(T, R)(scope R delegate(T) f, in T a, in T b,
    scope bool delegate(T lo, T hi) tolerance = (T a, T b) => false)
{
    return find root!(T, typeof(f), typeof(tolerance))(f, a, b, tolerance);
}

[9il]

moved

[9il]

rebased

[9il]

Thanks @MartinNowak. This overload works (I thought it wouldn't work.)!