function templates conflict with aliases

[dlangBugzillaToGithub]

monarchdodra reported this on 2014-01-05T13:34:13Z

Transferred from https://issues.dlang.org/show_bug.cgi?id=11873

Description

Apparently, this is according to spec, but I think it should be legal.

Simple functions? No problem:
//----
void foo();
void bar(int);

alias foo = bar;

void main()
{
    foo();
    foo(5);
}
//----

Templates? Problem:
//----
void foo()(); //Template here
void bar(int);

alias foo = bar;

void main()
{
    foo();
    foo(5);
}
//----
main.d(4): Error: alias main.foo conflicts with template main.foo()() at main.d(1)
//----

I think there should not be such a conflict. There is no reason for the alias not to work.

The above code is trivial, but a real world scenario where this can happen, is when a module wants to publicly import a named template function overload:

A.d
//----
module a;
foo(int); //Special "int" overload 
//----

B.d
//----
module b;
foo()(); //Standard 0-arg signature;
public import A : foo; //re-use "int"
//----

Because of this,

[dlangBugzillaToGithub]

monarchdodra commented on 2014-01-05T13:37:52Z

(In reply to comment #0)
> Templates? Problem:
> //----
> void foo()(); //Template here
> void bar(int);
> 
> alias foo = bar;
> 
> void main()
> {
>     foo();
>     foo(5);
> }
> //----
> main.d(4): Error: alias main.foo conflicts with template main.foo()() at
> main.d(1)
> //----
> 
> I think there should not be such a conflict. There is no reason for the alias
> not to work.

Just to be clear, I think this should be legal, as there is absolutly no conflict between the original symbol, and the alias anyways.

Perfectly legal:
//----
void foo()();
void foo(int);

void main()
{
    foo();
    foo(5);
}
//----

If that works, why does the alias create a conflict?