The rank of private first class has existed since 1846 and, prior to 1919, its insignia consisted of the branch of service insignia without any arcs or chevrons. The Secretary of War approved "an arc of one bar" (i.e., a "rocker") under the branch of service or trade insignia for privates first class on 22 July 1919.
The First Class seats were either available as fully closed suites (First Suite on Airbus A380 and select Boeing 777-200ER) or as open suite style flat-bed sleeper seats (Old First Class on Boeing 747-400). Between 2016 and 2018, First Class was eliminated from the Boeing 777-200ER fleet in favor of more Business Class and Economy Class seats.
A class with complex move and copy constructors may not be trivial, but it could be standard-layout and thus interoperate with C. Similarly, a class with public and private non-static data members would not be standard-layout, but it could be trivial and thus memcpy-able. Core language build-time performance enhancements Extern template