Question

I have ported some code from Mingw which i wrote using code::blocks, to visual studio and their compiler, it has picked up many errors that my array sizes must be constant! Why does VS need a constant size and mingw does not?

e.g.

const int len = (strlen(szPath)-20);
char szModiPath[len];

the len variable is underlined in red to say that its an error and says “expected constant expression”

The only way i can think to get around this is….

char* szModiPath = new char[len];
delete[] szModiPath;

Will i have to change everything to dynamic or is there another way in VS?

Answer 1

Why does VS need a constant size and mingw does not?

Because Variable Length Arrays are not a part of C++ although MinGW(g++) supports them as extension.
Array size has to be a constant expression in C++.

In C++ it is always recommended to use std::vector instead of C-style arrays. 🙂