Is it ok to use #pragma once instead of #define CROW_STUFF_H in crow's header files?

[Nabzokek]

This isn't more than a suggestion, but I think that use #pragma once isn't the more recommended way to define header files, considering we want to make CrowCpp a cross platform library.

When you search for #pragma once in the project files you will see so much files with this line.

This is not so bad, but maybe it would be better if we use #define CROW_THING_H in the library header files instead of the not standard #pragma once lines.

[gittiver]

It would make sense to add header guards and to leave pragma in addition in the file.
#pragma once is non standard but supported by most compilers.

So we should end up with:
#ifdef CROW_THING_H
#define CROW_THING_H
#pragma once
...
#endif /* #ifdef CROW_THING_H */

[Nabzokek]

It seems fine to me, but in that case, using the #pragma once would no longer make sense, because header guards already solve that problem.
We can leave the #pragma once as well, but I don't think it would make much sense anymore.

[gittiver]

It would only help a little bit on compile times (for some compilers).