bbox class is not detectable in S4 methods

[sigmafelix]

st_bbox() output has class that is reported when class() is run, however, when a S4 method tries to utilize this information, I encounter a "no definition for class bbox" error.

Reproducible example

library(sf)
dd <- st_bbox(c(xmin = 16.1, xmax = 16.6, ymax = 48.6, ymin = 47.9), crs = st_crs(4326))
class(dd)
[1] "bbox"

setGeneric("detect_bbox", function(x){})
[1] "detect_bbox"
setMethod("detect_bbox", signature = c(x = "bbox"), function(x){class(x)})
# in method for ‘detect_bbox’ with signature ‘x="bbox"’: no definition for class “bbox”

With sf class object, S4 method works properly:

library(sf)
ncsf_path <- system.file("shape/nc.shp", package = "sf")
ncsf <- st_read(ncsf_path)

setGeneric("detect_sf_col", function(x){})
setMethod("detect_sf_col", signature = c(x = "sf"), function(x) names(x))
detect_sf_col(ncsf)
# [1] "AREA"      "PERIMETER" "CNTY_"     "CNTY_ID"   "NAME"      "FIPS"
# [7] "FIPSNO"    "CRESS_ID"  "BIR74"     "SID74"     "NWBIR74"   "BIR79"
#[13] "SID79"     "NWBIR79"   "geometry"

[edzer]

You may need to S4 register the class, using setOldClass("bbox"), so that S4 can dispatch on it. It would be reasonable to assume sf does this, but that has not happened so far:

$ grep setOld *R
init.R:setOldClass("sf")
init.R:setOldClass(c("sfc_POINT", "sfc"))
init.R:setOldClass(c("sfc_MULTIPOINT", "sfc"))
init.R:setOldClass(c("sfc_LINESTRING", "sfc"))
init.R:setOldClass(c("sfc_MULTILINESTRING", "sfc"))
init.R:setOldClass(c("sfc_POLYGON", "sfc"))
init.R:setOldClass(c("sfc_MULTIPOLYGON", "sfc"))
init.R:setOldClass(c("sfc_GEOMETRY", "sfc"))
init.R:setOldClass(c("sfc_GEOMETRYCOLLECTION", "sfc"))
init.R:setOldClass("sfg")
init.R:setOldClass("crs")
sgbp.R:setOldClass("sgbp")
sp.R:setOldClass("XY")

[sigmafelix]

Thank you for the prompt response and the new push.