| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| google.golang.org/protobuf/encoding/protowire | Package protowire parses and formats the raw wire encoding. |
| google.golang.org/protobuf/internal/pragma | Package pragma provides types that can be embedded into a struct to statically enforce or prevent certain language properties. |
| math | Package math provides basic constants and mathematical functions. |
| regexp | Package regexp implements regular expression search. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| unsafe | Package unsafe contains operations that step around the type safety of Go programs. |