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//TODO potentially move HeaderTryFrom to `mail-headers` use error::ComponentCreationError; //TODO replace with std TryFrom once it is stable // (either a hard replace, or a soft replace which implements HeaderTryFrom if TryFrom exist) /// Workaround for `TryFrom`,`TryInto` not being stable. pub trait HeaderTryFrom<T>: Sized { fn try_from(val: T) -> Result<Self, ComponentCreationError>; } /// Workaround for `TryFrom`,`TryInto` not being stable. pub trait HeaderTryInto<T>: Sized { fn try_into(self) -> Result<T, ComponentCreationError>; } impl<F, T> HeaderTryInto<T> for F where T: HeaderTryFrom<F> { fn try_into(self) -> Result<T, ComponentCreationError> { T::try_from(self) } } impl<T> HeaderTryFrom<T> for T { fn try_from(val: T) -> Result<Self, ComponentCreationError> { Ok( val ) } } // It is not possible to auto-implement HeaderTryFrom for From/Into as // this will make new HeaderTryFrom implementations outside of this care // nearly impossible making the trait partially useless // //impl<T, F> HeaderTryFrom<F> for T where F: Into<T> { // fn try_from(val: F) -> Result<T, Error> { // Ok( val.into() ) // } //}