x <- sample(10)
x
vec_slice(x, 1:3)
# You can assign with the infix variant:
vec_slice(x, 2) <- 100
x
# Or with the regular variant that doesn't modify the original input:
y <- vec_assign(x, 3, 500)
y
x
# Slicing objects of higher dimension:
vec_slice(mtcars, 1:3)
# Type stability --------------------------------------------------
# The assign variant is type stable. It always returns the same
# type as the input.
x <- 1:5
vec_slice(x, 2) <- 20.0
# `x` is still an integer vector because the RHS was cast to the
# type of the LHS:
vec_ptype(x)
# Compare to `[<-`:
x[2] <- 20.0
vec_ptype(x)
# Note that the types must be coercible for the cast to happen.
# For instance, you can cast a double vector of whole numbers to an
# integer vector:
vec_cast(1, integer())
# But not fractional doubles:
try(vec_cast(1.5, integer()))
# For this reason you can't assign fractional values in an integer
# vector:
x <- 1:3
try(vec_slice(x, 2) <- 1.5)
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