remap

    fn remap(ctx: *anyopaque, memory: []u8, alignment: Alignment, new_len: usize, _: usize) ?[*]u8 {
        @disableInstrumentation();

        const f: *FuzzSingleThreadedAllocator = @ptrCast(@alignCast(ctx));
        if (f.smith.value(bool)) {
            const resized = FuzzSingleThreadedAllocator.resize(
                ctx,
                memory,
                alignment,
                new_len,
                undefined,
            );
            return if (resized) memory.ptr else null;
        }

        const i = f.allocIndex(memory, alignment);
        if (f.smith.value(bool)) return null;

        const new_ptr = f.allocInner(new_len, alignment) orelse return null;
        const copy_len = @min(memory.len, new_len);
        @memcpy(new_ptr[0..copy_len], memory[0..copy_len]);

        f.allocs.set(i, .{
            .ptr = new_ptr,
            .len = new_len,
            .alignment = alignment,
        });
        return new_ptr;
    }