Linker anomalies

[user5678]

On Thursday, 7 November 2019 at 12:14:43 UTC, Luh wrote:
> Hey there,
>
> I figured out some strange behavior ;
>
> #1
> It seems that the linker doesn't check for the function 
> declared twice first.
> Instead, it says:
>
> "Error: class app.Child use of app.Parent.foo() is hidden by 
> Child; use alias foo = Parent.foo; to introduce base class 
> overload set"
>
> but when we call it ( p.foo() ), then it returns the correct 
> error message.
>
> #2
> The template update() compiles fine until we call it.
>
> Bizarre, isn't it ?
>
> code:
> ---
> void main()
> {
> 	auto p = new Parent();
> 	// Shows the wrong error message until uncommented
> 	//p.foo();
> 	// Compiles when commented
> 	//update(p);
> }
>
> class Child : Parent
> {
> 	override void foo() { }
> }
>
> class Parent
> {
> 	void foo() { }
> 	void foo() { }
> }
>
> void update(T)(T object) if(is(T == Parent))
> {
> 	static if (is(T == Parent))
> 	{
> 		// Shouldn't compile
> 		ObjectThatDoesntExists.bar(T);
> 	}
> }
> ---
>
> Is this a bug ?

The diagnostic might be bad but at least the compiler doesn't 
crash, yay, woohoo !