What does =+ mean in C?

Question

I came across =+ as opposed to the standard += today in some C code; I\'m not quite sure what\'s going on here. I also couldn\'t find it in the doc

Answer 1

I think

a =+ 5;

should be equivalent to

a = (+5);

and therefore be code of very bad style.

I tried the following code and it printed "5":

#include 
using namespace std;

int main()
{
    int a=2;
    a =+ 5;
    cout << a;
}