EV

pub const EV = switch (native_os) {
    .driverkit, .ios, .maccatalyst, .macos, .tvos, .visionos, .watchos => struct {
        // https://github.com/apple-oss-distributions/xnu/blob/main/bsd/sys/event.h
        /// add event to kq (implies enable)
        pub const ADD = 0x0001;
        /// delete event from kq
        pub const DELETE = 0x0002;
        /// enable event
        pub const ENABLE = 0x0004;
        /// disable event (not reported)
        pub const DISABLE = 0x0008;
        /// only report one occurrence
        pub const ONESHOT = 0x0010;
        /// clear event state after reporting
        pub const CLEAR = 0x0020;
        /// force immediate event output
        /// ... with or without ERROR
        /// ... use KEVENT_FLAG_ERROR_EVENTS
        ///     on syscalls supporting flags
        pub const RECEIPT = 0x0040;
        /// disable event after reporting
        pub const DISPATCH = 0x0080;
        /// unique kevent per udata value
        pub const UDATA_SPECIFIC = 0x0100;
        /// ... in combination with DELETE
        /// will defer delete until udata-specific
        /// event enabled. EINPROGRESS will be
        /// returned to indicate the deferral
        pub const DISPATCH2 = DISPATCH | UDATA_SPECIFIC;
        /// report that source has vanished
        /// ... only valid with DISPATCH2
        pub const VANISHED = 0x0200;
        /// reserved by system
        pub const SYSFLAGS = 0xF000;
        /// filter-specific flag
        pub const FLAG0 = 0x1000;
        /// filter-specific flag
        pub const FLAG1 = 0x2000;
        /// EOF detected (return value)
        pub const EOF = 0x8000;
        /// error, data contains errno (return value)
        pub const ERROR = 0x4000;
        /// use poll(2) semantics for EVFILT.READ
        pub const POLL = FLAG0;
        /// on input, filter should actively return in the presence of OOB on the descriptor
        /// on output, indicates the presence of OOB data on the descriptor
        pub const OOBAND = FLAG1;
    },
    .dragonfly => struct {
        pub const ADD = 1;
        pub const DELETE = 2;
        pub const ENABLE = 4;
        pub const DISABLE = 8;
        pub const ONESHOT = 16;
        pub const CLEAR = 32;
        pub const RECEIPT = 64;
        pub const DISPATCH = 128;
        pub const NODATA = 4096;
        pub const FLAG1 = 8192;
        pub const ERROR = 16384;
        pub const EOF = 32768;
        pub const SYSFLAGS = 61440;
    },
    .netbsd => struct {
        /// add event to kq (implies enable)
        pub const ADD = 0x0001;
        /// delete event from kq
        pub const DELETE = 0x0002;
        /// enable event
        pub const ENABLE = 0x0004;
        /// disable event (not reported)
        pub const DISABLE = 0x0008;
        /// only report one occurrence
        pub const ONESHOT = 0x0010;
        /// clear event state after reporting
        pub const CLEAR = 0x0020;
        /// force EV_ERROR on success, data=0
        pub const RECEIPT = 0x0040;
        /// disable event after reporting
        pub const DISPATCH = 0x0080;
        /// filter-specific flag
        pub const FLAG1 = 0x2000;
        /// error, data contains errno
        pub const ERROR = 0x4000;
        /// EOF detected
        pub const EOF = 0x8000;
    },
    .freebsd => struct {
        // https://cgit.freebsd.org/src/tree/sys/sys/event.h
        /// add event to kq (implies enable)
        pub const ADD = 0x0001;
        /// delete event from kq
        pub const DELETE = 0x0002;
        /// enable event
        pub const ENABLE = 0x0004;
        /// disable event (not reported)
        pub const DISABLE = 0x0008;
        /// enable _ONESHOT and force trigger
        pub const FORCEONESHOT = 0x0100;
        /// do not update the udata field
        pub const KEEPUDATA = 0x0200;
        /// only report one occurrence
        pub const ONESHOT = 0x0010;
        /// clear event state after reporting
        pub const CLEAR = 0x0020;
        /// force immediate event output
        /// ... with or without ERROR
        /// ... use KEVENT_FLAG_ERROR_EVENTS
        ///     on syscalls supporting flags
        pub const RECEIPT = 0x0040;
        /// disable event after reporting
        pub const DISPATCH = 0x0080;
        /// reserved by system
        pub const SYSFLAGS = 0xF000;
        /// note should be dropped
        pub const DROP = 0x1000;
        /// filter-specific flag 1
        pub const FLAG1 = 0x2000;
        /// filter-specific flag 2
        pub const FLAG2 = 0x4000;
        /// EOF detected (return value)
        pub const EOF = 0x8000;
        /// error, event data contains errno (return value)
        pub const ERROR = 0x4000;
    },
    .openbsd => struct {
        pub const ADD = 0x0001;
        pub const DELETE = 0x0002;
        pub const ENABLE = 0x0004;
        pub const DISABLE = 0x0008;
        pub const ONESHOT = 0x0010;
        pub const CLEAR = 0x0020;
        pub const RECEIPT = 0x0040;
        pub const DISPATCH = 0x0080;
        pub const FLAG1 = 0x2000;
        pub const ERROR = 0x4000;
        pub const EOF = 0x8000;
    },
    .haiku => struct {
        /// add event to kq (implies enable)
        pub const ADD = 0x0001;
        /// delete event from kq
        pub const DELETE = 0x0002;
        /// enable event
        pub const ENABLE = 0x0004;
        /// disable event (not reported)
        pub const DISABLE = 0x0008;
        /// only report one occurrence
        pub const ONESHOT = 0x0010;
        /// clear event state after reporting
        pub const CLEAR = 0x0020;
        /// force immediate event output
        /// ... with or without ERROR
        /// ... use KEVENT_FLAG_ERROR_EVENTS
        ///     on syscalls supporting flags
        pub const RECEIPT = 0x0040;
        /// disable event after reporting
        pub const DISPATCH = 0x0080;
    },
    else => void,
}