hasFields

import mir.algorithm.iteration : filter;

static struct Foo
{
    int i;
}

auto ar = [Foo(1), Foo(3), Foo(4), Foo(17)];

auto filtered1 = ar.filter!"a.i & 1";
auto filtered2 = ar.filter!"!(a.i & 1)";

import mir.ser.json: serializeJson;
assert(serializeJson(filtered1) == `[{"i":1},{"i":3},{"i":17}]`);
assert(serializeJson(filtered2) == `[{"i":4}]`);

import mir.ser.json: serializeJson;
uint[2] ar = [1, 2];
assert(serializeJson(ar) == `[1,2]`);
assert(serializeJson(ar[]) == `[1,2]`);
assert(serializeJson(ar[0 .. 0]) == `[]`);
assert(serializeJson((uint[]).init) == `[]`);