do you ever use

when

for just two cases for clarity? e.g.

enum class Foo {
    FOO, BAR
}

fun foo(foo: Foo): Int = when(foo) {
    FOO -> "foo"
    BAR -> "bar"
}

or is this basically a no-no, because an single

if

else

can handle it? e.g.

fun foo(foo: Foo) = if (foo == FOO) "foo" else "bar"

I would definitely use

when

here.

I tend to find

when

clearer even in non-enum cases:

fun foo(foo: Int) = when(foo) {
    2 -> "two"
    else -> "not two"
}

Maybe I just like the syntax more, or the way everything lines up. The blocking of it, etc

I agree, if it is an expression and whole

if

would not fit into one line, then I would use

when

in some cases too 🙂

I also use when usually. It improves readibility.

it's also great considering in math/boolean logical notation,

A -> B

represents

if A then B

and so it matches that.