At what point is the initialized value of a variable passed to the defer statement, and how is this related to the function's naming?

In Go, function arguments, including those used in the defer statement, are evaluated at the moment of the defer call, not when the deferred function actually executes.

This means that if a variable is passed to defer, its value is fixed at the time of the defer declaration, even if the deferred function executes later, for example, after the function exits.

Example:

func example() (result int) {
    x := 5
    defer fmt.Println("defer x:", x) // x is fixed here, equal to 5
    x = 10
    return x
}

When calling example(), the output will be "defer x: 5", even though at the return point, x is already 10.

Regarding named return values, defer can modify them if the deferred function accesses them directly:

func example() (result int) {
    defer func() {
        result += 1 // modify the named result
    }()
    result = 5
    return // returns 6 after defer execution
}

Thus, defer fixes argument values at declaration but can influence named return values if they are modified inside the deferred function.