bind_cols() allows duplicate column names

[tiernanmartin]

As @hadley noted, this is likely a bug.

df1 <- mtcars %>% select(mpg,cyl,disp) %>% slice(1:5)
df2 <- mtcars %>% select(mpg,hp,drat) %>% slice(6:10)

names(one);names(two)
## [1] "mpg"  "cyl"  "disp"
## [1] "mpg"  "hp"   "drat"

df_combined <- bind_cols(df1,df2)

df_combined
## mpg cyl disp  mpg  hp drat
## 1 21.0   6  160 18.1 105 2.76
## 2 21.0   6  160 14.3 245 3.21
## 3 22.8   4  108 24.4  62 3.69
## 4 21.4   6  258 22.8  95 3.92
## 5 18.7   8  360 19.2 123 3.92

df_combined %>% select(mpg)
## Error: found duplicated column name: mpg

Seems like a good opportunity to add a suffix argument, as seen in the dplyr::*_join() verbs.

[krlmlr]

Thanks. Please see #2232 for a PR.

[hadley]

I've dispatched to tibble::repair_names(). This will eventually be responsible for generating a message.