is_bm_bitmap() returns TRUE for bm_bitmap objects (or subclasses)
and FALSE for all other objects.
Examples
space_matrix <- matrix(0L, nrow = 16L, ncol = 16L)
is_bm_bitmap(space_matrix)
#> [1] FALSE
space_glyph <- bm_bitmap(space_matrix)
is_bm_bitmap(space_glyph)
#> [1] TRUE