Array Operations and type inference

[simendsjo]

I'm new to D2, so please.. :)

The spec on Array Operations, 
http://www.digitalmars.com/d/2./arrays.html says:
"""A vector operation is indicated by the slice operator appearing as 
the lvalue of an =, +=, -=, *=, /=, %=, ^=, &= or |= operator."""

The following tests works fine as I expected:


	{
		double[3] a = [1,1,1];
		double[3] b;
		b[] = a[] + 3;
		assert(a == [1,1,1]);
		assert(b == [4,4,4]);
	}
	
	{
		double[3] a = [1,1,1];
		auto b = a;
		b[] = a[] + 3;
		assert(a == [1,1,1]);
		assert(b == [4,4,4]);
	}

But from here on I'm having problems...

	{
		double[] a = [1,1,1];
		double[] b;
		b[] = a[] + 3;
		assert(a == [1,1,1]);
		assert(b == [4,4,4]); // fails as b.length == 0.. Should the compiler 
say something?
	}
	
	{
		double[] a = [1,1,1];
		double[] b;
		b.length = a.length;
		b[] = a[] + 3;
		assert(a == [1,1,1]);
		assert(b == [4,4,4]); // Now it's fine
	}
	
	{
		double[3] a = [1,1,1];
		double[3] b = a[] + 3; // works although lvalue isn't a slice. Static 
arrays? Because it's an initial value?
		assert(a == [1,1,1]);
		assert(b == [4,4,4]);
	}
	
	{
		double[3] a = [1,1,1];
		auto b = a;
		b = a[] + 3; // And so does this.. Something to do with static arrays?
		assert(a == [1,1,1]);
		assert(b == [4,4,4]);
	}
	
	{ // Like the previous example, but with dynamic arrays..
		double[] a = [1,1,1];
		auto b = a;
		assert(a is b);
		b = a[] + 3;
		assert(a == [1,1,1]);
		//writeln(b); // access violation. Because of dynamic arrays?
	}	

	{ // Like above, but using slicing like the spec says.. Works fine
		double[] a = [1,1,1];
		auto b = a;
		assert(a is b);
		writeln(typeof(b).stringof); // double[]
		b[] = a[] + 3;
		assert(a == [4,4,4]); // a also changed. I expected this
		assert(b == [4,4,4]);
	}
	
	{
		double[3] a = [1,1,1];
		auto b = a[] + 3; // What happens here?
		writeln(typeof(b).stringof); // double[]
		assert(b.length == 3);
		assert(b.capacity == 0);
		//writeln(b); // access violation
	}
	
	{ // Same as above?
		double[3] a = [1,1,1];
		//writeln(a[] + 3); // access violation
	}