What is the purpose of the unary plus (+) operator in C?

Question

In C, it\'s legal to write something like:

int foo = +4;

However, as far as I can tell, the unary plus (+) in +4

Answer 1

Not precisely a no-op

The unary + operator does only one thing: it applies the integer promotions. Since those would occur anyway if the operand were used in an expression, one imagines that unary + is in C simply for symmetry with unary -.

It's difficult to see this in action because the promotions are so generally applied.

I came up with this:

printf("%zd\n", sizeof( (char) 'x'));
printf("%zd\n", sizeof(+(char) 'x'));

which (on my Mac) prints

1
4