How to fix C++ error: 'stoi' is not a member of 'std'

Problem

When compiling C++ code, you may encounter the following error message:

/home/uli/myproject/main.cpp:162:26: error: 'stoi' is not a member of 'std'
  162 |                 g = std::stoi(argv[3])

Solution

You need to include the <string> header in your C++ code.

The stoi function is part of the C++ standard library and is defined in the <string> header.

Add this line at the top of your C++ file:

#include <string>

After that, try to compile your code again. The error should be resolved.