Single build-time switch for the deprecated v1 Cw-form compatibility entries.

Copyright

Apache License, Version 2.0. Copyright (C) 2026 Yulong Ming i@myl.nosp@m.7.or.nosp@m.g.

Author

Yulong Ming i@myl.nosp@m.7.or.nosp@m.g

FSS_ENABLE_V1_COMPAT is the only definition site of the switch. It is a numeric macro: the default 1 keeps the deprecated Cw-form overloads, the deprecated aggregate-Key entries, and their companion types available, and an explicit 0 removes them so only the current split-component APIs remain.

Define it to the same value in every translation unit of a program, including ones that only include FSS headers indirectly. The scheme classes gain or lose members with this macro, so mixed settings create distinct class definitions and violate the one-definition rule.