Primitive Type i161.0.0[−]
Expand description
16 位带符号整数类型。
Implementations
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn rotate_left(self, n: u32) -> i16
1.0.0 (const: 1.32.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn rotate_left(self, n: u32) -> i16
1.0.0 (const: 1.32.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn rotate_right(self, n: u32) -> i16
1.0.0 (const: 1.32.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn rotate_right(self, n: u32) -> i16
1.0.0 (const: 1.32.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_add(self, rhs: i16) -> Option<i16>
1.0.0 (const: 1.47.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_add(self, rhs: i16) -> Option<i16>
1.0.0 (const: 1.47.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const unsafe fn unchecked_add(self, rhs: i16) -> i16
[src]🔬 This is a nightly-only experimental API. (unchecked_math
#85122)
niche optimization path
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const unsafe fn unchecked_add(self, rhs: i16) -> i16
[src]🔬 This is a nightly-only experimental API. (unchecked_math
#85122)
niche optimization path
未经检查的整数加法。
假设不会发生溢出,则计算 self + rhs
。
Safety
当以下情况时,这导致未定义的行为
self + rhs > i16::MAX
or self + rhs < i16::MIN
,
i.e. 当 checked_add
返回 None
时。
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_sub(self, rhs: i16) -> Option<i16>
1.0.0 (const: 1.47.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_sub(self, rhs: i16) -> Option<i16>
1.0.0 (const: 1.47.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const unsafe fn unchecked_sub(self, rhs: i16) -> i16
[src]🔬 This is a nightly-only experimental API. (unchecked_math
#85122)
niche optimization path
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const unsafe fn unchecked_sub(self, rhs: i16) -> i16
[src]🔬 This is a nightly-only experimental API. (unchecked_math
#85122)
niche optimization path
未经检查的整数减法。
假设不会发生溢出,则计算 self - rhs
。
Safety
当以下情况时,这导致未定义的行为
self - rhs > i16::MAX
or self - rhs < i16::MIN
,
i.e. 当 checked_sub
返回 None
时。
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_mul(self, rhs: i16) -> Option<i16>
1.0.0 (const: 1.47.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_mul(self, rhs: i16) -> Option<i16>
1.0.0 (const: 1.47.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const unsafe fn unchecked_mul(self, rhs: i16) -> i16
[src]🔬 This is a nightly-only experimental API. (unchecked_math
#85122)
niche optimization path
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const unsafe fn unchecked_mul(self, rhs: i16) -> i16
[src]🔬 This is a nightly-only experimental API. (unchecked_math
#85122)
niche optimization path
未经检查的整数乘法。
假设不会发生溢出,则计算 self * rhs
。
Safety
当以下情况时,这导致未定义的行为
self * rhs > i16::MAX
or self * rhs < i16::MIN
,
i.e. 当 checked_mul
返回 None
时。
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_div(self, rhs: i16) -> Option<i16>
1.0.0 (const: 1.52.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_div(self, rhs: i16) -> Option<i16>
1.0.0 (const: 1.52.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_div_euclid(self, rhs: i16) -> Option<i16>
1.38.0 (const: 1.52.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_div_euclid(self, rhs: i16) -> Option<i16>
1.38.0 (const: 1.52.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_rem(self, rhs: i16) -> Option<i16>
1.7.0 (const: 1.52.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_rem(self, rhs: i16) -> Option<i16>
1.7.0 (const: 1.52.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_rem_euclid(self, rhs: i16) -> Option<i16>
1.38.0 (const: 1.52.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_rem_euclid(self, rhs: i16) -> Option<i16>
1.38.0 (const: 1.52.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_shl(self, rhs: u32) -> Option<i16>
1.7.0 (const: 1.47.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_shl(self, rhs: u32) -> Option<i16>
1.7.0 (const: 1.47.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const unsafe fn unchecked_shl(self, rhs: i16) -> i16
[src]🔬 This is a nightly-only experimental API. (unchecked_math
#85122)
niche optimization path
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const unsafe fn unchecked_shl(self, rhs: i16) -> i16
[src]🔬 This is a nightly-only experimental API. (unchecked_math
#85122)
niche optimization path
未检查的左移。
计算 self << rhs
,假设 rhs
小于 self
中的位数。
Safety
如果 rhs
大于或等于 self
中的位数,则会导致未定义的行为,即
当 checked_shl
返回 None
时。
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_shr(self, rhs: u32) -> Option<i16>
1.7.0 (const: 1.47.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_shr(self, rhs: u32) -> Option<i16>
1.7.0 (const: 1.47.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const unsafe fn unchecked_shr(self, rhs: i16) -> i16
[src]🔬 This is a nightly-only experimental API. (unchecked_math
#85122)
niche optimization path
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const unsafe fn unchecked_shr(self, rhs: i16) -> i16
[src]🔬 This is a nightly-only experimental API. (unchecked_math
#85122)
niche optimization path
未检查右移。
计算 self >> rhs
,假设 rhs
小于 self
中的位数。
Safety
如果 rhs
大于或等于 self
中的位数,则会导致未定义的行为,即
当 checked_shr
返回 None
时。
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_pow(self, exp: u32) -> Option<i16>
1.34.0 (const: 1.50.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_pow(self, exp: u32) -> Option<i16>
1.34.0 (const: 1.50.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn saturating_add(self, rhs: i16) -> i16
1.0.0 (const: 1.47.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn saturating_add(self, rhs: i16) -> i16
1.0.0 (const: 1.47.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn saturating_sub(self, rhs: i16) -> i16
1.0.0 (const: 1.47.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn saturating_sub(self, rhs: i16) -> i16
1.0.0 (const: 1.47.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn saturating_mul(self, rhs: i16) -> i16
1.7.0 (const: 1.47.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn saturating_mul(self, rhs: i16) -> i16
1.7.0 (const: 1.47.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn saturating_pow(self, exp: u32) -> i16
1.34.0 (const: 1.50.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn saturating_pow(self, exp: u32) -> i16
1.34.0 (const: 1.50.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_add(self, rhs: i16) -> i16
1.0.0 (const: 1.32.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_add(self, rhs: i16) -> i16
1.0.0 (const: 1.32.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_sub(self, rhs: i16) -> i16
1.0.0 (const: 1.32.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_sub(self, rhs: i16) -> i16
1.0.0 (const: 1.32.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_mul(self, rhs: i16) -> i16
1.0.0 (const: 1.32.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_mul(self, rhs: i16) -> i16
1.0.0 (const: 1.32.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_div(self, rhs: i16) -> i16
1.2.0 (const: 1.52.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_div(self, rhs: i16) -> i16
1.2.0 (const: 1.52.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_div_euclid(self, rhs: i16) -> i16
1.38.0 (const: 1.52.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_div_euclid(self, rhs: i16) -> i16
1.38.0 (const: 1.52.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_rem(self, rhs: i16) -> i16
1.2.0 (const: 1.52.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_rem(self, rhs: i16) -> i16
1.2.0 (const: 1.52.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_rem_euclid(self, rhs: i16) -> i16
1.38.0 (const: 1.52.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_rem_euclid(self, rhs: i16) -> i16
1.38.0 (const: 1.52.0)[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_shl(self, rhs: u32) -> i16
1.2.0 (const: 1.32.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_shl(self, rhs: u32) -> i16
1.2.0 (const: 1.32.0)[src]无 Panic - 按位左移; 产生 self << mask(rhs)
,其中 mask
删除 rhs
的所有高位,这些高位将导致移位超过该类型的位宽。
注意,这与左旋不同; 环绕左移的 RHS 限于该类型的范围,而不是从 LHS 移出的位返回到另一端。
所有原始整数类型都实现了 rotate_left
函数,而您可能想要的是 rotate_left
函数。
Examples
基本用法:
assert_eq!((-1i16).wrapping_shl(7), -128); assert_eq!((-1i16).wrapping_shl(128), -1);Run
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_shr(self, rhs: u32) -> i16
1.2.0 (const: 1.32.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_shr(self, rhs: u32) -> i16
1.2.0 (const: 1.32.0)[src]无 Panic - 按位右移; 产生 self >> mask(rhs)
,其中 mask
删除 rhs
的所有高位,这些高位将导致移位超过该类型的位宽。
注意,这与右旋转不同。换行右移的 RHS 限于类型的范围,而不是从 LHS 移出的位返回到另一端。
所有原始整数类型都实现了 rotate_right
函数,而您可能想要的是 rotate_right
函数。
Examples
基本用法:
assert_eq!((-128i16).wrapping_shr(7), -1); assert_eq!((-128i16).wrapping_shr(64), -128);Run
包装 (modular) 绝对值。计算 self.abs()
,在类型的边界处回绕。
可能发生这种换行的唯一情况是,当类型取负的最小值的绝对值时; 这是一个太大的正值,无法在类型中表示。
在这种情况下,此函数将返回 MIN
本身。
Examples
基本用法:
assert_eq!(100i16.wrapping_abs(), 100); assert_eq!((-100i16).wrapping_abs(), 100); assert_eq!(i16::MIN.wrapping_abs(), i16::MIN); assert_eq!((-128i8).wrapping_abs() as u8, 128);Run
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_pow(self, exp: u32) -> i16
1.34.0 (const: 1.50.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn wrapping_pow(self, exp: u32) -> i16
1.34.0 (const: 1.50.0)[src]计算 self
的绝对值。
返回 self 的绝对版本的元组以及一个布尔值,该布尔值指示是否发生了溢出。 如果 self 是最小值 (e.g., i16::MIN for values of type i16), 然后将再次返回最小值,并在发生溢出时返回 true。
Examples
基本用法:
assert_eq!(10i16.overflowing_abs(), (10, false)); assert_eq!((-10i16).overflowing_abs(), (10, false)); assert_eq!((i16::MIN).overflowing_abs(), (i16::MIN, true));Run
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn div_euclid(self, rhs: i16) -> i16
1.38.0 (const: 1.52.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn div_euclid(self, rhs: i16) -> i16
1.38.0 (const: 1.52.0)[src]计算 self
的欧几里得除以 rhs
的商。
这将计算整数 q
,使得 self = q * rhs + r
、r = self.rem_euclid(rhs)
和 0 <= r < abs(rhs)
。
换句话说,结果是 self / rhs
舍入为整数 q
,使得 self >= q * rhs
。
如果为 self > 0
,则等于舍入为零 (Rust 中的默认值) ;
如果为 self < 0
,则等于朝 +/- 无限取整。
Panics
如果 rhs
为 0 或除法导致溢出,则该函数将为 panic。
Examples
基本用法:
let a: i16 = 7; // or any other integer type let b = 4; assert_eq!(a.div_euclid(b), 1); // 7 >= 4 * 1 assert_eq!(a.div_euclid(-b), -1); // 7 >= -4 * -1 assert_eq!((-a).div_euclid(b), -2); // -7 >= 4 * -2 assert_eq!((-a).div_euclid(-b), 2); // -7 >= -4 * 2Run
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn rem_euclid(self, rhs: i16) -> i16
1.38.0 (const: 1.52.0)[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn rem_euclid(self, rhs: i16) -> i16
1.38.0 (const: 1.52.0)[src]计算 self (mod rhs)
的最小非负余数。
就像通过欧几里得除法算法一样 - 给定 r = self.rem_euclid(rhs)
,self = rhs * self.div_euclid(rhs) + r
和 0 <= r < abs(rhs)
。
Panics
如果 rhs
为 0 或除法导致溢出,则该函数将为 panic。
Examples
基本用法:
let a: i16 = 7; // or any other integer type let b = 4; assert_eq!(a.rem_euclid(b), 3); assert_eq!((-a).rem_euclid(b), 1); assert_eq!(a.rem_euclid(-b), 3); assert_eq!((-a).rem_euclid(-b), 1);Run
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn log(self, base: i16) -> i16
[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn log(self, base: i16) -> i16
[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn log2(self) -> i16
[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn log2(self) -> i16
[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn log10(self) -> i16
[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn log10(self) -> i16
[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_log(self, base: i16) -> Option<i16>
[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_log(self, base: i16) -> Option<i16>
[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_log2(self) -> Option<i16>
[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_log2(self) -> Option<i16>
[src]#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_log10(self) -> Option<i16>
[src]
#[must_use = "this returns the result of the operation, \ without modifying the original"]pub const fn checked_log10(self) -> Option<i16>
[src]将此整数的内存表示作为本机字节顺序的字节数组返回。
由于使用了目标平台的原生字节序,因此,可移植代码应酌情使用 to_be_bytes
或 to_le_bytes
。
Examples
let bytes = 0x1234i16.to_ne_bytes(); assert_eq!( bytes, if cfg!(target_endian = "big") { [0x12, 0x34] } else { [0x34, 0x12] } );Run
从其表示形式以 big endian 的字节数组形式创建一个整数值。
Examples
let value = i16::from_be_bytes([0x12, 0x34]); assert_eq!(value, 0x1234);Run
从切片而不是数组开始时,可以使用容易出错的转换 API:
use std::convert::TryInto; fn read_be_i16(input: &mut &[u8]) -> i16 { let (int_bytes, rest) = input.split_at(std::mem::size_of::<i16>()); *input = rest; i16::from_be_bytes(int_bytes.try_into().unwrap()) }Run
从它的表示形式以 little endian 的字节数组形式创建一个整数值。
Examples
let value = i16::from_le_bytes([0x34, 0x12]); assert_eq!(value, 0x1234);Run
从切片而不是数组开始时,可以使用容易出错的转换 API:
use std::convert::TryInto; fn read_le_i16(input: &mut &[u8]) -> i16 { let (int_bytes, rest) = input.split_at(std::mem::size_of::<i16>()); *input = rest; i16::from_le_bytes(int_bytes.try_into().unwrap()) }Run
从其内存表示形式创建一个整数值,以原生字节序表示为字节数组。
由于使用了目标平台的原生字节序,因此可移植代码可能希望酌情使用 from_be_bytes
或 from_le_bytes
。
Examples
let value = i16::from_ne_bytes(if cfg!(target_endian = "big") { [0x12, 0x34] } else { [0x34, 0x12] }); assert_eq!(value, 0x1234);Run
从切片而不是数组开始时,可以使用容易出错的转换 API:
use std::convert::TryInto; fn read_ne_i16(input: &mut &[u8]) -> i16 { let (int_bytes, rest) = input.split_at(std::mem::size_of::<i16>()); *input = rest; i16::from_ne_bytes(int_bytes.try_into().unwrap()) }Run
👎 Deprecating in a future Rust version: replaced by the MIN
associated constant on this type
replaced by the MIN
associated constant on this type
新代码应优先使用
i16::MIN
instead.
返回此整数类型可以表示的最小值。
Trait Implementations
执行 +=
操作。 Read more
执行 +=
操作。 Read more
执行 &=
操作。 Read more
执行 &=
操作。 Read more
type Output = NonZeroI16
type Output = NonZeroI16
应用 |
运算符后的结果类型。
执行 |
操作。 Read more
执行 |=
操作。 Read more
执行 |=
操作。 Read more
执行 ^=
操作。 Read more
执行 ^=
操作。 Read more
此运算将舍入为零,舍去精确结果的任何小数部分。
Panics
This operation will panic if other == 0
or the division results in overflow.
执行 /=
操作。 Read more
执行 /=
操作。 Read more
Converts a NonZeroI16
into an i16
type Err = ParseIntError
type Err = ParseIntError
可以从解析中返回的相关错误。
执行 *=
操作。 Read more
执行 *=
操作。 Read more
如果存在,则此方法返回 self
和 other
值之间的顺序。 Read more
此操作满足 n % d == n - (n / d) * d
。
结果具有与左操作数相同的符号。
Panics
This operation will panic if other == 0
or if self / other
results in overflow.
执行 %=
操作。 Read more
执行 %=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 <<=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
执行 >>=
操作。 Read more
🔬 This is a nightly-only experimental API. (step_trait
#42168)
recently redesigned
返回通过将 self
count
的 successor 而获得的值。 Read more
🔬 This is a nightly-only experimental API. (step_trait
#42168)
recently redesigned
返回通过获取 self count
次的 predecessor 而获得的值。 Read more
🔬 This is a nightly-only experimental API. (step_trait
#42168)
recently redesigned
返回通过将 self
count
的 successor 而获得的值。 Read more
🔬 This is a nightly-only experimental API. (step_trait
#42168)
recently redesigned
返回通过获取 self count
次的 predecessor 而获得的值。 Read more
🔬 This is a nightly-only experimental API. (step_trait
#42168)
recently redesigned
返回从 start
到 end
所需的 successor 步骤的数量。 Read more
执行 -=
操作。 Read more
执行 -=
操作。 Read more