"ABS" problem :/ overloaded functions

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C++14

ambigious call to overloaded function. Cant fix it and i dont know how abs's work, just trying to fix a code and use it to make a cheat for a video game haha.
Any help would be appreciated if you can rewrite that line for me i'd appreciate it alot.

What I have tried:

float GetWavRoll(Vector dir)
{
	Vector forward(1, -dir.x, dir.y);

	Vector up(0, -dir.x, abs(dir.y + (1 / dir.y) + (1 / dir.y)));

	if (dir.x > 0 && dir.y < 0)
		up.y = abs(up.y);
	else if (dir.x < 0 && dir.y < 0)
		up.y = -abs(up.y);

	Vector left = up.Cross(forward);

	float roll = deg(atan2f(left.z, (left.y * forward.x) - (left.x * forward.y)));
}