What is the purpose of using the function context.WithValue in managing execution context in Go?

The context.WithValue function in Go is used to create a new context that contains a key-value pair. This allows passing additional data through a chain of function calls without changing their signatures.

The main purpose is to provide a safe and convenient way to pass information related to a request or operation, such as user identifiers, settings, or metadata.

Example of usage:

ctx := context.Background()
ctxWithValue := context.WithValue(ctx, "userID", 42)

// In a function accepting ctx:
userID := ctx.Value("userID")
if userID != nil {
    fmt.Println("User ID:", userID)
}

It is important not to use context.WithValue for passing large structures or for controlling logic, but only for small, immutable data related to the execution context.