In practice it isn't a big deal.

Assuming you've got the source to everything

If you're using closed-source C++ libraries, you need to be sure that the vendor has compiled it using the exact same compiler (and compiler options) to what you need...

It would probably be better to just ask the vendor to give you a C version of their library instead

well maybe i do not wrote it clearry but I was asking about c interface libs? you talking about c++?

As i said It seem to me that this c (c interface) libs are also incompatible (has incompatible interfaces?) but also I suspect that this incompatibility is not major - isnt this just a metter of symbols?

specifically i wold be most curious what is a reason between incompatibility of c - like static libs made with VS against those of GCC/mingw

In practice it isn't a big deal.

Assuming you've got the source to everything

In two decades, with teams as small as 5 people, I have not seen it as an actual problem. Maybe it is a problem for other people.

This big is relative ;/ I understand what you say , but still maybe it is not very big deal but still some deal ;\ Really static libs are done to work, as i said if they could work it is bad that they do not work ;\

Also it is really so easy to complie sources?, i am using mingw (presently i dont even know how to use make) Is there easy to compile sources made with VS, they probably use different build systems or something.. I got not a practice in it

(also some sources (for quite interestin things) are made with some old compilers, i remember vaguelly i was trying to get some lib for c-interpreter (so I could use c scripts, it was fun idea, big advantages) wasnt it cint or something? but it was old and I get no skills to compile it, if this would be just lib (even old) i could use it, but old (and messy as big sources are always not redeable and undertstandable to me) sources

seemed unusable to me

what with that ? ;/