forked from boostorg/detail
IIRC it's `class` in SGI's STL and most other implementations. The state for similar warnings for the compilers that I've looked at: - Visual C++ never warns because I used a pragma to disable the warning. - GCC never warns with its standard library since it contains a `system_header` pragma. It might warn for other libraries. - Clang respects GCC's pragma so it never warns for GCC's standard library. Forward declarations are disabled for libc++ so this isn't an issue there. It does warn when using Dinkumware and possibly other standard libraries. I'm tempted to make container forwarding 'opt-in' rather than 'opt-out'. Or maybe only enable for compiler/library combinations where it's known to work. [SVN r75561]