Data commit

Task/Identity-matrix/D/identity-matrix.d

@@ -0,0 +1,30 @@
+import std.traits;
+
+T[][] matId(T)(in size_t n) pure nothrow if (isAssignable!(T, T)) {
+    auto Id = new T[][](n, n);
+
+    foreach (r, row; Id) {
+        static if (__traits(compiles, {row[] = 0;})) {
+            row[] = 0; // vector op doesn't work with T = BigInt
+            row[r] = 1;
+        } else {
+            foreach (c; 0 .. n)
+                row[c] = (c == r) ? 1 : 0;
+        }
+    }
+
+    return Id;
+}
+
+void main() {
+    import std.stdio, std.bigint;
+    enum form = "[%([%(%s, %)],\n %)]]";
+
+    immutable id1 = matId!real(5);
+    writefln(form ~ "\n", id1);
+
+    immutable id2 = matId!BigInt(3);
+    writefln(form ~ "\n", id2);
+
+    // auto id3 = matId!(const int)(2); // cant't compile
+}