How to use character category inside regexp search?


#1
‘\cC’
     matches any character whose category is C.  Here C is a character
     that represents a category: thus, ‘c’ for Chinese characters or ‘g’
     for Greek characters in the standard category table.  You can see
     the list of all the currently defined categories with ‘M-x
     describe-categories <RET>’.  You can also define your own
     categories in addition to the standard ones using the
     ‘define-category’ function (*note Categories::).

‘[ ... ]’
     is a “character alternative”, which begins with ‘[’ and is
     terminated by ‘]’.  In the simplest case, the characters between
     the two brackets are what this character alternative can match.

     Thus, ‘[ad]’ matches either one ‘a’ or one ‘d’, and ‘[ad]*’ matches
     any string composed of just ‘a’s and ‘d’s (including the empty
     string).  It follows that ‘c[ad]*r’ matches ‘cr’, ‘car’, ‘cdr’,
     ‘caddaar’, etc.
Example:
    ht 删掉 t 我 p 删掉 s 我: 删我 / 删我 /w 删我 w 删我 w 删我. 删我 ex 删我 am 删我 ple 删我 . 删我 co 删掉 m 我 / 删我 i7 删我 mx 删我 ss 删我 d

M-x isearch-forward-regexp RET \(\cc\| \)

then replace it with empty string gives the result of 
`https://www.example.com/i7mxssd`

but I wonder how to use \cc inside [] instead of \(\cc\| \)


#2

[ ... ] 不支持 Character Category,文档没说的都表示不支持。