How to Deprecate a Function or Package in Go

Deprecate a function or package in Go by adding a // Deprecated: comment immediately before the declaration. This comment must start with the word "Deprecated" followed by a space and a brief explanation of why it is deprecated and what to use instead.

// Deprecated: Use TypeReg instead.
const TypeRegA = '\x00'

// Deprecated: Use Modified instead.
var ModifiedTime uint16

The go command and documentation tools automatically detect this comment and mark the symbol as deprecated in generated documentation and API diffs.

Deprecation in Go is a way to tell users that a specific feature is old and should not be used in new code. You do this by adding a special comment above the code that explains why it is being phased out and suggests a better alternative. This helps developers update their code gradually without breaking existing programs immediately.