Enum SeekWhence 

#[repr(i32)]
pub enum SeekWhence {
    Set = 0,
    Cur = 1,
    End = 2,
}

文件偏移量设置模式

用于 lseek() 系统调用 对应 POSIX 的 SEEK_SET、SEEK_CUR、SEEK_END 参考：include/uapi/linux/fs.h

Variants

Set = 0

从文件开头计算 (SEEK_SET)

Cur = 1

从当前位置计算 (SEEK_CUR)

End = 2

从文件末尾计算 (SEEK_END)

Implementations

impl SeekWhence

pub fn from_i32(value: i32) -> Option<Self>

从 i32 转换（用于系统调用参数解析）

参数

• value: 用户空间传入的 whence 值（0/1/2）

返回值

• Some(whence): 有效的 whence 值
• None: 无效值

pub fn from_usize(value: usize) -> Option<Self>

从 usize 转换（兼容旧代码）

Trait Implementations

impl Clone for SeekWhence

fn clone(&self) -> SeekWhence

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SeekWhence

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for SeekWhence

fn eq(&self, other: &SeekWhence) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for SeekWhence

impl Eq for SeekWhence

impl StructuralPartialEq for SeekWhence