Check if vector is constant
Examples
x <- rep(9, 1000000)
is_constant(x)#> [1] TRUEx[10] <- NA
is_constant(x)#> [1] FALSEis_constant(x, skip_missing = TRUE)#> [1] TRUECheck if vector is constant
x <- rep(9, 1000000)
is_constant(x)#> [1] TRUEx[10] <- NA
is_constant(x)#> [1] FALSEis_constant(x, skip_missing = TRUE)#> [1] TRUE