Have instances of a generic function

[f3c0]

Can I have an instance of a generic function?

For example I have a function like this:

function pushType<T>(item: T, list: T[]): T[]{
    list.push(item);
    return list;
}

If I would like to use with number parameter in multiple places, I have to do this:

pushType<number>(12, [3, 4, 5]);
pushType<number>(1, [4, 5]);

Can I have an instance of this function for numbers instead of?
Something like this:

var pushNumber = pushType<number>; // this is syntax error now
pushNumber(12, [3, 4, 5]);
pushNumber(1, [4, 5]);

var pushNumber = pushType<number>; is now synax error and compiles to var pushNumber = pushType();
It would be nice I guess to compile it to var pushNumber = pushType;

[CyrusNajmabadi]

You can just do:

var pushNumber: (i: number, list: number[]) => number[] = pushType;

[danquirk]

Note there's no need to explicitly specify the generic type argument here.

function pushType<T>(item: T, list: T[]): T[]{
    list.push(item);
    return list;
}

pushType(12, [3, 4, 5]); // ok
pushType(1, [4, 5]); // ok
pushType(1, ['']); // error

[f3c0]

Thanks danquirk. No need to explicit specify in that case, I agree.
However if I have the var pushNumber = pushType<number>; than a pushNumber('1', ['2']); is an error while the pushType('1', ['2']); is fine, so it's like a restricted version of a generic function.

CyrusNajmabadi's comment looks a solution for now, thanks. But I feel my my suggesion more elegant. Do you think is it against any language design or can it be a valid suggestion to implement later?

[danquirk]

You might also be interested in #1616

The problem right now is that the system is not designed in such a way that you can instantiate a generic with a particular type and then 'finish' using it later (ie provide arguments). Certainly people are accustomed to doing something like what you are proposing in certain other languages with different implementations of generics. Given that there are a couple good workarounds (Cyrus' as well as defining a separate function constrained specifically to number which then forwards the call to a more generic version) we would likely need some more compelling use cases to consider complicating the type system like this.