https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83756
--- Comment #3 from Jacob Godserv <jacobgodserv at gmail dot com> --- Created attachment 43078 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43078&action=edit mingw-w64 5.4.0 TestClass.ii I've attached gcc's intermediate output to make this even easier to reproduce. Compile it like so: x86_64-5.4.0-release-win32-seh-rt_v5-rev0/mingw64/bin/g++ -std=c++11 TestClass.ii