Question

C declaration syntax is fairly convoluted …

Which brings me to my question regarding casting syntax,

Simple types are easy enough, just put the type in brackets.
But what about types like,

int (*2Dap) [5]; or double (*fp) (double, double);

I guessing here, the rule is to just strip away the identifier (plus the semicolon) of a normal variable declaration and put it in brackets.

So, int (*2Dap) [5]; becomes ( int (*) [5] ) and char * str; becomes just (char *)

Is this a general rule?

As so typedef, your new “type” would be what is your “variable” in your typedef declaration,

eg. typedef double (*twoINoneOUT) (double, double); “twoInoneOUT” would be your new “type”.

Correct??

Just wanted to clarify. I know I’m unlikely to even need to cast these – could save me from having to typedef unnecessarily though.

Answer 1

I guessing here, the rule is to just strip away the identifier (plus
the semicolon) of a normal variable declaration and put it in
brackets.

Right. This declares a variable called x:

int (*x)[5];

The type of the variable is int (*)[5], and you could cast to that type using the cast (int (*)[5]).

As so typedef, your new “type” would be what is your “variable” in
your typedef declaration,

Also correct. This declares a type alias called t:

typedef int (*t)[5];

Syntactically, typedef appears in the same place as a storage class specifier like static.