As a special exception, you may use this file as part of a free software
library without restriction. Specifically, if other files instantiate
templates or use macros or inline functions from this file, or you compile
this file and link it with other files to produce an executable, this
file does not by itself cause the resulting executable to be covered by
the GNU General Public License. This exception does not however
invalidate any other reasons why the executable file might be covered by
the GNU General Public License.
We really can't give you legal advice on licensing; we can just tell you what the licensing is.
However, you might find the Q&A portion following the actual license text at http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/license.html helpful. I note that there the FSF says: "Hopefully that text is self-explanatory. If it isn't, you need to speak to your lawyer, or the Free Software Foundation.
Q: So any program which uses libstdc++ falls under the
A: No. The special exception permits use of the library in proprietary applications."
Well, legal advice is one thing, and I understand that nobody here can provide any kind legal counseling,but I'd be interested in what the original intention behind the choice was. Are we supposed to use the open source version of TBB in commercial applications, even if we need to modify the original code?