Error on scroll texture shader based on Alan Zucconi's book - unity3d

Question

Using unity 5.5 and Alan Zucconi's book I'm getting " incorrect number of arguments to numeric-type constructor"
shader source added as reccommended:
Shader "book/scroller"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
_ScrollXSpeed ("x scroll speed", Range(0,10)) = 2
_ScrollYSpeed("Y scroll speed", Range(0,10)) = 2
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
};
sampler2D _MainTex;
float4 _MainTex_ST;
fixed _ScrollXSpeed;
fixed _ScrollYSpeed;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
UNITY_TRANSFER_FOG(o,o.vertex);
return o;
}
fixed4 frag (v2f i) : SV_Target
{
fixed2 scrolledUV = i.uv;
fixed2 xScrolledValue = _ScrollXSpeed * _Time;
fixed2 yScrolledValue = _ScrollYSpeed * _Time;
scrolledUV += fixed2 (xScrolledValue, yScrolledValue);
fixed4 col = tex2D(_MainTex, scrolledUV);
return col;
}
ENDCG
}
}
}
Error shows at following line:
scrolledUV += fixed2 (xSCrolledValue, ySCrolledValue);
What is wrong with it?

Answer 1

Reason for the error:
You are creating fixed2-variable and giving it two fixed2 values as parameters, should be floats instead.
Here is a fixed version:
fixed xScrolledValue = _ScrollXSpeed * _Time;
fixed yScrolledValue = _ScrollYSpeed * _Time;
scrolledUV += fixed2 (xScrolledValue, yScrolledValue);