The read_* functions now bring in data as a tibble (because of bfee48b). However, the reindexing in geos_op2_df means st_intersection.sf still returns an ordinary data.frame. st_sym_difference and st_difference are the same; all three depend on geos_op2_df.

library(sf)
library(tidyverse)
nc <- read_sf(system.file("shape/nc.shp", package = "sf"))
class(nc)
#> [1] "sf"         "tbl_df"     "tbl"        "data.frame"

class(st_intersection(nc, nc))
#> [1] "sf"         "data.frame"

Ref: #404

Footnote: data.table sf objects, when they get implemented, will probably also need special treatment here, since both tibble and data.table change the definition of [.. cc @rafapereirabr