There's a lot of other junk going around my code related to the rest of the project, but what I'm struggling with is the code for the hangman minigame.
I'm new to coding and open to any suggestions on my program, but I'm mostly interested in fixing this bug. I cannot for the life of me figure out what this is, and am pretty sure that it's something simple that I'm too much of an idiot to see.
The error message:
/tmp/ccxoZJvp.o: In function `main':
/home/main.cpp:184: undefined reference to `letterFill(char, std::string, std::string&)'
collect2: error: ld returned 1 exit status
The code for the program itself: