Re: [go-nuts] Question about "interface{}" convert to "string"

Chris's answer is correct, but a little out of date. Now error objects have
an Error method instead of a String method. But it still returns a string.
Do a type assertion to the new error interface.

Might be simpler to just return an error instead of panic()'ing.
Normally less interface {} involved in that.

If you want the least amount of work, then use (similar to what OP
suggests), fmt.Sprint(x), the downside is that it is does far more work as
it makes a new string each time. The upside is that it should handle most
types (including numeric types). Alternatively, if the only thing you are
going to do is hand it to a fmt.* or log.* function, you could just leave
it as an interface{} and let the function you call "stringify" it for
you: http://play.golang.org/p/Ygq9nD75PF

Otherwise, if maximizing speed or minimizing string creation is important
than you can use type switches / type assertions and / or reflect. Here
I've created a toString method which, if possible, uses a method / feature
of the type to avoid the extra work and the extra string conversion that
fmt.SPrint* functions have to do. http://play.golang.org/p/fHs2ABo1c0

Also, there's an additional advantage that I can write custom string
representations for types I don't have the ability to modify (see time.Time
example).

That first sentence is a little confusing here's a (hopefully clearer)
rewrite:

For the least amount of programmer work, you can use fmt.Sprint(x) to
convert anything to a string the same way that fmt.* functions do. This is
slightly less efficient than some other solutions, since the fmt.*
functions were made to handle concatenation efficiently, and thus do their
work on []byte slices, which requires extra conversion steps and results in
new strings being made.