Shouldn't be this "=+" a syntax error?

Question

Recently I was trying to use the following code:

int number = 4;
number += other_variable;//2
...
printf("Number:%d\n",number);//-->6

but I had an error typing and instead I've got this code:

int number = 4;
number =+ other_variable;//2
...
printf("Number:%d\n",number);//-->2

Apparently this compiled with gcc 4.7.3 and gcc 4.4.3 and the result was as a normal assignment operator. The question is: Shouldn't be this a syntax error?

Answer 1

No - this is being parsed as:

number = +other_variable;

i.e. you have assignment and a unary + operator. You're reading it as =+ but it's two separate operators, = and +.

Answer 2

No, it's just a null op.

number = +other_variable;
number = 0 + other_variable;

As a complement to these operations, which negate:

number =- other_variable;
number = -other_variable;
number = 0 - other_variable;