[ios.seekdir]
31 Input/output library [input.output]
31.5 Iostreams base classes [iostreams.base]
31.5.2 Class ios_base [ios.base]
31.5.2.2 Types [ios.types]
31.5.2.2.5 Type ios_base::seekdir [ios.seekdir]
using seekdir = T4;
The type seekdir is an enumerated type ([enumerated.types]) that contains the elements indicated in Table 140.