Efficient way to remove first and last elements of a vector

Three different ways to remove first and last elements of a vector are compared. The winner is without contest: v[-c(1, length(v))]

> v <- 1:100
> head(v[-1], -1)
 [1]  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
[30] 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59
[59] 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88
[88] 89 90 91 92 93 94 95 96 97 98 99
> rev(rev(v[-1])[-1])
 [1]  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
[30] 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59
[59] 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88
[88] 89 90 91 92 93 94 95 96 97 98 99
> v[-c(1, length(v))]
 [1]  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
[30] 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59
[59] 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88
[88] 89 90 91 92 93 94 95 96 97 98 99

> system.time(for(i in 1:100000) head(v[-1], -1))
utilisateur     système      écoulé
      2.427       0.072       2.502
> system.time(for(i in 1:100000) rev(rev(v[-1])[-1]))
utilisateur     système      écoulé
      2.157       0.203       2.422
> system.time(for(i in 1:100000) v[-c(1, length(v))])
utilisateur     système      écoulé
      0.329       0.039       0.368

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