Subset for all except certain words / patterns using stringr?

all-except.R

library(stringr)

# I had something like this
bobs <- c("bob.txt", "bob.scn", "bob")

# I want to remove just the strings with "scn"
# Using: https://stackoverflow.com/questions/5556213/regex-to-match-everything-except-the-given-words-which-may-include-hyphens-dash
str_subset(bobs, "^(?:(?!scn).)*$")
#> [1] "bob.txt" "bob"

# Also just realizing I can do
bobs[!str_detect(bobs, "scn")]
#> [1] "bob.txt" "bob"

# With that in mind, I'd rather be able to do something like:
str_ignore <- function(string, pattern) {
  string[!str_detect(string, pattern)]
} 

str_ignore(bobs, "scn")
#> [1] "bob.txt" "bob"

str_ignore(bobs, "scn|txt")
#> [1] "bob"

# This is basically the opposite of what str_subset does right?
# Might be a useful extra function?
# Or is there an easier way with str_subset?