++
prefix
pre-increment by 1

⚛++
prefix numeric
atomic pre-increment by 1

--
prefix
pre-decrement by 1

⚛--
prefix numeric
atomic pre-decrement by 1

++
postfix
post-increment by 1

⚛++
postfix numeric
atomic post-increment by 1

--
postfix
post-decrement by 1

⚛--
postfix numeric
atomic post-decrement by 1


contains the infix operators for incrementing / decrementing (usually)
numeric values.

The atomic versions of C<--> and C<++> were implemented for 6.d.  They
can only be applied to atomic integers.
