Georg Baum 51cc8aa9f6 Fix build with GNU libstdc++ C++11 ABI
The GNU libstdc++ that ships witch gcc 5 can be used with the same ABI as
older versions, or with a new ABI which is conformant to the C++11 standard.
LyX did not build if the latter was used:
https://kojipkgs.fedoraproject.org//work/tasks/1267/9651267/build.log

This is now fixed by detecting the ABI version and disabling the wrong forward
declarations. At the same time, STD_STRING_USES_COW is switched off for the
C++11 ABI version, because the std::basic_string implementation is now C++11
conformant. Since the GNU libstdc++ can also used by other compilers such as
clang, we must not test for the compiler version.
2015-05-08 21:12:42 +02:00
..
2015-05-06 17:08:56 +02:00
2006-08-06 20:45:31 +00:00
2015-01-11 19:44:35 +01:00