Add ? to C operator highlighting

after/syntax/c.vim

@@ -7,13 +7,14 @@
 "                              ^    ^ ^    ^ ^ ^
 syn match cDelimiter '[()\[\]{}:;]'
 " Match single character operators, ordering within the [] is important
-syn match cOperator '[\*=\.\^\~+-,&|!%]'
+syn match cOperator '[\*=\.\^\~+-,&|!%?]'
 " Match single character operators if they are surrounded by white space: / < >
 "                                                                         ^ ^ ^
 syn match cOperator '\(\s\zs\/\s\ze\|\s\zs<\s\ze\|\s\zs>\s\ze\)'
 " Match multi character operators
 syn match cOperator '\(+=\|-=\|\*=\|/=\|%=\|\ˆ=\|&=\||=\|<<\|>>\|>>=\)'
 syn match cOperator '\(<<=\|==\|!=\|<=\|>=\|&&\|||\|++\|--\|->\*\|->\)'
+" TODO: Match : in ternary operator as cOperator
 " Match function expressions: expr()
 "                             ^^^^
 syn match cFunction '\w[A-Za-z0-9_]*\ze\s*('