While coding, one comments and uncomments a lot while optimising and testing the code, which means adding and deleting the /* */ by hand. With the following syntax hack you only need to delete one slash to comment or uncomment a section.
/* foo1 (); foo2 (); ... // */
Once you add an extra / to the /* comment block, the block gets uncommented.
//* foo1 (); foo2 (); ... // */