as.logical() returns a logical(0):

as.logical()
#> logical(0)

but I’m surprised to see that logical(0) is much slower than as.logical(). Why is that? This is also the case for the other as.*() functions:

bench::mark(as.logical(), logical(0), iterations = 1e5)
#> # A tibble: 2 × 6
#>   expression        min   median `itr/sec` mem_alloc `gc/sec`
#>                 
#> 1 as.logical()   48.1ns     76ns  8467061.        0B      0  
#> 2 logical(0)      468ns    571ns  1541503.        0B     30.8
bench::mark(as.character(), character(0), iterations = 1e5)
#> # A tibble: 2 × 6
#>   expression          min   median `itr/sec` mem_alloc `gc/sec`
#>                   
#> 1 as.character()     65ns   94.1ns  9734069.        0B      0  
#> 2 character(0)      505ns    593ns  1550503.        0B     15.5
bench::mark(as.numeric(), numeric(0), iterations = 1e5)
#> # A tibble: 2 × 6
#>   expression        min   median `itr/sec` mem_alloc `gc/sec`
#>                 
#> 1 as.numeric()   58.1ns     91ns 10218252.        0B      0  
#> 2 numeric(0)      500ns    561ns  1622768.        0B     16.2
bench::mark(as.integer(), integer(0), iterations = 1e5)
#> # A tibble: 2 × 6
#>   expression        min   median `itr/sec` mem_alloc `gc/sec`
#>                 
#> 1 as.integer()     64ns     92ns  9863536.        0B      0  
#> 2 integer(0)      469ns    582ns  1435752.        0B     14.4