In C$++$

Given two functions:

int extractInt$($const char src$[],$ int& index,int& depth$),$ which extracts the first few digits from array src$[]$ until ecountering a $"\{",$ and converting into integers, i$.$e$.$ char src$[]="4321\{$a$\}72\{$b$\}"$ would only return $4321$ in integer form, and is safe to assume the first characters until the first $"\{"$ are all digits.

Another function void repeatString$($char str$[],$ int repeat$\_$times, char repeated$\_$str$[])$ would repeat str$[]($repeat$\_$times$)$ times and save into repeated$\_$str$[],$ i$.$e$.$ for str$[]=$ "abd", repeat$\_$times $=3,$ repeated$\_$str would be "abdabdabd".

Use these two defined functions to constuct another function:

void recursiveDecode$($const char src$[],$ int& index, char decoded$[]),$

where src$[]$ would be the input string, and decoded$[]$ would be the decoded string, demonstrated below:

src$[]="$a$2\{$ba$\}"-->$ decoded$[]=$ ababa

src$[]=\text{'}$ab$3\{$a$1\{$b$\{2\{$fb$\}\}\}\}\text{'}-->$ decoded$[]=$ ababfbfabfbfabfbfb

In other words, the strings in the brackets would be repeated multiple times determined by the integers before it$,$ where the integers could be many digits.

It can be assumed that $\{\}$ would only have integers before it$,$ i$.$e$.2\{$a$\},$ while a$\{$a$\}$ would be invalid and would not appear in the inputs. Nested brackets however, are possible.

Write the final function in terms of the functions defined, with no added parameters, only usable libraries are and $.$

And DO NOT use any while or for loops for the function, only recursion is allowed