Bug 2641 – std.variant Variant's check for "can append" is wrong

The code below used in std.variant seems to be assuming that if a type can be indexed, then it can also be appended to: ----- case OpID.catAssign: auto me = cast(A*) pStore; static if (is(typeof((*me)[0])) && !is(typeof(me.keys))) { // array type; parm is the element to append auto arg = cast(VariantN*) parm; alias typeof((*me)[0]) E; if (arg[0].convertsTo!(E)) { // append one element to the array (*me) ~= [ arg[0].get!(E) ]; } else { // append a whole array to the array (*me) ~= arg[0].get!(A); } --- This causes it to fail when trying to use a fixed-length struct, like a fixed vec3 that provides an opIndex but no opCatAssign.

Fixed in future 2.032 (and checked in for the impatient).