| withr-package | Execute code in temporarily altered environment | 
| defer | Defer Evaluation of an Expression | 
| deferred_clear | Defer Evaluation of an Expression | 
| deferred_run | Defer Evaluation of an Expression | 
| defer_parent | Defer Evaluation of an Expression | 
| devices | Graphics devices | 
| local_bmp | Graphics devices | 
| local_cairo_pdf | Graphics devices | 
| local_cairo_ps | Graphics devices | 
| local_collate | Collation Order | 
| local_connection | Connections which close themselves | 
| local_db_connection | DBMS Connections which disconnect themselves. | 
| local_dir | Working directory | 
| local_environment | Execute code with a modified search path | 
| local_envvar | Environment variables | 
| local_file | Files which delete themselves | 
| local_jpeg | Graphics devices | 
| local_language | Language | 
| local_libpaths | Library paths | 
| local_locale | Locale settings | 
| local_makevars | Makevars variables | 
| local_message_sink | Output redirection | 
| local_namespace | Execute code with a modified search path | 
| local_options | Options | 
| local_output_sink | Output redirection | 
| local_package | Execute code with a modified search path | 
| local_par | Graphics parameters | 
| local_path | PATH environment variable | 
| local_pdf | Graphics devices | 
| local_png | Graphics devices | 
| local_postscript | Graphics devices | 
| local_preserve_seed | Random seed | 
| local_rng_version | RNG version | 
| local_seed | Random seed | 
| local_svg | Graphics devices | 
| local_tempdir | Temporary files and directories | 
| local_tempfile | Temporary files and directories | 
| local_temp_libpaths | Library paths | 
| local_tiff | Graphics devices | 
| local_timezone | Time zone | 
| local_xfig | Graphics devices | 
| withr | Execute code in temporarily altered environment | 
| with_bmp | Graphics devices | 
| with_cairo_pdf | Graphics devices | 
| with_cairo_ps | Graphics devices | 
| with_collate | Collation Order | 
| with_connection | Connections which close themselves | 
| with_db_connection | DBMS Connections which disconnect themselves. | 
| with_dev | Graphics devices | 
| with_device | Graphics devices | 
| with_dir | Working directory | 
| with_environment | Execute code with a modified search path | 
| with_envvar | Environment variables | 
| with_file | Files which delete themselves | 
| with_gctorture2 | Torture Garbage Collector | 
| with_jpeg | Graphics devices | 
| with_language | Language | 
| with_libpaths | Library paths | 
| with_locale | Locale settings | 
| with_makevars | Makevars variables | 
| with_message_sink | Output redirection | 
| with_namespace | Execute code with a modified search path | 
| with_options | Options | 
| with_output_sink | Output redirection | 
| with_package | Execute code with a modified search path | 
| with_par | Graphics parameters | 
| with_path | PATH environment variable | 
| with_pdf | Graphics devices | 
| with_png | Graphics devices | 
| with_postscript | Graphics devices | 
| with_preserve_seed | Random seed | 
| with_rng_version | RNG version | 
| with_seed | Random seed | 
| with_sink | Output redirection | 
| with_svg | Graphics devices | 
| with_tempdir | Temporary files and directories | 
| with_tempfile | Temporary files and directories | 
| with_temp_libpaths | Library paths | 
| with_tiff | Graphics devices | 
| with_timezone | Time zone | 
| with_xfig | Graphics devices |