> (size)(sizeof(x)[y]) Actually, and this is probably surprising to many, this is equivalent to (size)(sizeof ((x)[y])) sizeof is not a function but a un

> (size)(sizeof(x)[y]) Actually, and this is probably surprising to many, this is equivalent to (size)(sizeof ((x)[y])) sizeof is not a function but a unary operator, and indexing (as well as function calling...) binds stronger than the sizeof operator. It is not a function, not even syntactically! Hence why I strongly prefer putting a space after the sizeof keyword, and to not use parens for the operand unless needed. https://en.cppreference.com/w/c/language/operator_precedence https://en.cppreference.com/w/c/language/operator_precedence So the "correct" way to define the macro is #define sizeof(x) ((size)(sizeof (x)))