ๅ ธๅ็ใซ`Error<T::Error, U::Error>`ใฎใใใชๅฝขใงไฝฟใใใๅค็ธใช`Error`ใฎ็ฅ่จใจใใฆใ`type FooError<T, U> = Error<<T as Trait1>::Error, <U as Trait2>::Error>`ใฎใใใชๅฅๅใๅฎ็พฉใใใใฎใ ใใฉใใใฃใใๆฅใๅๅใๆตฎใใฐใชใ
ๅใใใใๆป
่ถ่ฆ่ถ้ใซ`ErrorFor`ใจใๅฝๅใใฆใใใใใฉใใใใไฝใงใ้ใใใใไธๅฟ`type Result<T, U, V> = core::result::Result<T, ErrorFor<U, V>`ใๅฎ็พฉใใฆๅ
ธๅ็ใชไพใงใฏ้ๅฝๅใ้ฟใใใใใใใซใใใใฎใฎใใใฏใใจใฉใผๅไฝใงๅๆใใใใใๅพใชใๅ ด้ขใใใใ
ไธๅฟ`Error`่ชไฝใฎๅฎ็พฉใ`enum Error<T: Trait1, U: Trait2>`ใซ็ฝฎใๆใใๆใใใใ ใใใใฉใๆ่ปๆงใไธใใใใๆใกๅใใจใใซ็ก้งใชใใฌใคใๅถ็ดใใบใซใ็บ็ใใใใชใฎใงใใใใ้ฟใใใใจใใ
