Question

What’s wrong with this one? The compiler says: Declaration syntax error.

Source File:

#include<iostream>
using namespace std;
int main(int argc, char **argv) {
    void printBinary(const unsigned char val) {
        //printBinary() func. outputs byte in binary
        for(int i=7;i>=0;i--)
            if(val & (1<<i))  //generates a single bit with offset position
                std::cout<<"1";
            else
                std::cout<<"0"
    }
    return 0;
}///:~

Header file:

void printBinary(const unsigned char val);
///:~

Answer 1

You are trying to define one function inside another function. This is illegal. Why did you place the definition of printBinary into the body of main?

Aside from the lambda functions in C++11, C++ has no such feature as local functions. All functions “live” in namespace scope.

The only workaround for this rule is inline member function definitions for local classes, although it does not produce a local function either.