| errors | Package errors implements functions to manipulate errors. |
| internal/bytealg | |
| internal/oserror | Package oserror defines errors values used in the os package. |
| io | Package io provides basic interfaces to I/O primitives. |
| path | Package path implements utility routines for manipulating slash-separated paths. |
| slices | Package slices defines various functions useful with slices of any type. |
| time | Package time provides functionality for measuring and displaying time. |
| unicode/utf8 | Package utf8 implements functions and constants to support text encoded in UTF-8. |