| errors | Package errors implements functions to manipulate errors. |
| internal/abi | |
| internal/bytealg | |
| internal/stringslite | Package stringslite implements a subset of strings, only using packages that may be imported by "os". |
| io | Package io provides basic interfaces to I/O primitives. |
| iter | Package iter provides basic definitions and operations related to iterators over sequences. |
| math/bits | Package bits implements bit counting and manipulation functions for the predeclared unsigned integer types. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| unicode | Package unicode provides data and functions to test some properties of Unicode code points. |
| unicode/utf8 | Package utf8 implements functions and constants to support text encoded in UTF-8. |
| unsafe | Package unsafe contains operations that step around the type safety of Go programs. |