rlang: is_copyable – R documentation

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is_copyable

Is an object copyable?

Description

When an object is modified, R generally copies it (sometimes lazily) to enforce value semantics. However, some internal types are uncopyable. If you try to copy them, either with <- or by argument passing, you actually create references to the original object rather than actual copies. Modifying these references can thus have far reaching side effects.

Usage

is_copyable(x)

Arguments

`x`	An object to test.

Examples

# Let's add attributes with structure() to uncopyable types. Since
# they are not copied, the attributes are changed in place:
env <- env()
structure(env, foo = "bar")
env

# These objects that can only be changed with side effect are not
# copyable:
is_copyable(env)

structure(base::list, foo = "bar")
str(base::list)

rlang

Functions for Base Types and Core R and 'Tidyverse' Features

v0.4.11

MIT + file LICENSE

Authors

Lionel Henry [aut, cre], Hadley Wickham [aut], mikefc [cph] (Hash implementation based on Mike's xxhashlite), Yann Collet [cph] (Author of the embedded xxHash library), RStudio [cph]

Initial release