Add a marker for post-C++17 APIs in exported classes

MSVC will export any function in an exported class, including inline
ones. Conversely: client code calling inline functions in imported
classes will end up simply calling the symbol of the function, even if
the function is fully inline.

This is a problem for adding post-C++17 APIs in Qt. Such APIs are added
as inline functions protected by feature-macro tests, so that both Qt
and client apps can use any C++ version they want (any combination
works).

However, if we add a function using post-C++17 API to an exported class,
then the combination "Qt built in C++17" + "client built in post-C++17"
won't work any more. The client will expect the symbol for that function
to be exported by Qt, but Qt won't have it (built in C++17).

As a workaround, add a marker that turns these functions into "faux
templates", like Q_WEAK_OVERLOAD does.

Change-Id: I2adab81e3129c881c5a8e0772948b176fa4db1b6
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

0 files changed, 0 insertions, 0 deletions