https://github.com/IliaFeldgun/cpp-noob/blob/01dbd16aabe106846e3bc9a19f9def34ac29343f/matrix.cpp#L21 https://learn.microsoft.com/en-us/cpp/standard-library/overloading-the-output-operator-for-your-own-classes?view=msvc-170
cpp-noob/matrix.cpp
Line 21 in 01dbd16
https://learn.microsoft.com/en-us/cpp/standard-library/overloading-the-output-operator-for-your-own-classes?view=msvc-170