Do pure functions solve the "return const" problems?

[Janice Caron]

On 02/04/2008, Steven Schveighoffer <schveiguy at yahoo.com> wrote:
>  If pure functions are not required to take invariant parameters, then they
>  cannot be guaranteed to be thread safe.

Well, that's an "if". My suspicion is that pure functions will require
invariant parameters. According to Wikipedia, in functional languages,
all data is invariant, so that makes sense.