[R] regular expression help

[C Lin]

Dear R users,

I need to match a string. It can be followed or preceded by whitespace or // or nothing.
How do I code it in R?

For example:
test <- c('AARSD11','AARSD1-','AARSD1//','AARSD1 //','//AARSD1');
grep('AARSD1(\\s*//*)',test);

should return 3,4,5 and 6.

Thanks in advance for your help.

Lin