I voted for the first option because I think it is mnemonic, but some of the others are also
With ->? it looks like the test comes after the deref.
+> & !> just look like typos.
->-> looks like a double deref, rather than a single conditional one.
I find all those using & anti-mnemonic in that elsewhere it takes a reference, rather than dereferences one.
And those containing = look much too much like a fat comma. The parser may be able to distinguish them, but I don't think my brain would.
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
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