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Understanding C/C++ style declarations!!!

There are certain rules known as Clockwise/Spiral rules to understand C/C++ style declarations.

It follows 3 simple rules:( see example below for better understanding).

1. Starting with the unknown element, move in a spiral/clockwise direction; when encountering the following elements replace them with the corresponding English statements:

• [X] or []=> Array X size of… or Array undefined size of…

• (type1, type2)=> function passing type1 and type2 returning…

• *=> pointer(s) to...

     2. Keep doing this in a spiral/clockwise direction until all tokens have been covered.     3. Always resolve anything in parenthesis first.

Example 1:

int* ptr;

We need to find, what is ptr?

Applying Spiral rule:

• ptr is a
• ptr is a pointer.. (because we encountered *)

Example 2:

char* str[10]

• str is an
• str is an array 10 of (we encountered [ )

Example 3:

const int* const ptr;

• ptr is a
• ptr is a constant

Limitations of spiral rule:

Example,

int (*foo[])();

Some cases where this rule cannot be applied.

•   []() – cannot have an array of functions
•   ()() – cannot have a function that returns a function
•   ()[] – cannot have a function that returns an array.

Source: http://stringfeed.xyz/