add Packed*Array::pop_back

[bend-n]

closes (what i need) of godotengine/godot-proposals#4637

[AThousandShips]

This is pretty trivial, just sugar for arr.resize(arr.size() - 1), I don't see the need for this

pop_back on the other hand

See here

[bend-n]

I'm not sure how to correctly implement pop_back.

[AThousandShips]

See the implementation in Array:

godot/core/variant/array.cpp

Lines 665 to 674 in 6916349

	Variant Array::pop_back() {
	ERR_FAIL_COND_V_MSG(_p->read_only, Variant(), "Array is in read-only state.");
	if (!_p->array.is_empty()) {
	const int n = _p->array.size() - 1;
	const Variant ret = _p->array.get(n);
	_p->array.resize(n);
	return ret;
	}
	return Variant();
	}

Would instead involve grabbing the last value, and then resizing back

[bend-n]

Is there no reason we have remove_at and not pop_at, then?

[AThousandShips]

Unsure, but could be because it has not been considered needed for general use of Vector

[AThousandShips]

Note that Array doesn't have remove_back, only pop_back

I'd argue that having a method that just does:

if not arr.is_empty():
    arr.resize(arr.size() - 1)

Is not needed, especially not added to a core component like Vector

[bend-n]

Im skeptical if

T pop_back() {
	ERR_FAIL_COND(_cowdata.size() == 0);
	T tmp = *_cowdata.get(_cowdata.size() - 1);
	_cowdata.resize(_cowdata.size() - 1);
	return tmp;
}

would work with gdscript and all

[AThousandShips]

That's why it should probably error for Packed*Array

T pop_back() {
	ERR_FAIL_COND_V(_cowdata.is_empty(), T());
	T tmp = *_cowdata.get(_cowdata.size() - 1);
	_cowdata.resize(_cowdata.size() - 1);
	return tmp;
}

Alternatively write a dedicated handler for just Typed*Array, like is done for PackedByteArray for some complex functionality

[bend-n]

I wonder if i ought to add pop_at, pop_front as well.

[AThousandShips]

I'd take that as a separate thing, also Vector doesn't have push_front so would be unbalanced to add the pop_front