Question

Already overloaded operators <<,>>,= etc are used many times.

An example that i was thinking of is when we add strings say :

string name = string(“munish”) + “kumar”;

the + operator is overloaded in the string class.

but when we add numbers like 1 + 2( doesn’t seem like an overloaded operator call)

I was just wondering how does it happens does the compiler does a binary additon.

I don’t need to worry about it much though if the compiler does it so, just a matter of curiosity for me.

Answer 1

Primitive types don’t implement operator+ which is actually a function with a weird name. Addition for Primitive type is carried out by CPU instruction such as :

addl %edx,(%eax) //this adds two integral values loaded at edx and eax

You implement operator+ for user-defined types, and compiler generates lots of CPU instructions to carry out the task which you write in operator+.