Re: Appending static arrays

[Nordlöw via Digitalmars-d-learn]

On Monday, 17 July 2017 at 20:01:41 UTC, H. S. Teoh wrote:
OK, here's an actual, compilable, runnable version:
        import std.algorithm : sum;
        import std.meta : allSatisfy, staticMap;
        import std.range : only;
        import std.traits : CommonType, isStaticArray;

        alias Elem(A : E[n], E, size_t n) = E;
        enum Length(A) = A.length;
        enum sumLengths(A...) = sum(only(0, staticMap!(Length, A)));

	CommonType!(staticMap!(Elem, A))[sumLengths!A] append(A...)(A 
arrays)
                if (allSatisfy!(isStaticArray, A))
        {
                typeof(return) result = void;
                foreach (i, a; arrays) {
                        enum offset = sumLengths!(A[0 .. i]);
                        result[offset .. offset + a.length] = a[];

This slice assignment doesn't support conversion between 
different element-types, for instance from `int[]` to `double[]`.

But I'm not convinced that we should allow `CommonType` when 
operator ~ doesn't.