Add is_err_or to Result utils.

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/utils/result.rs

@@ -4,6 +4,7 @@ mod filter;
 mod flat_ok;
 mod inspect_log;
 mod into_is_ok;
+mod is_err_or;
 mod log_debug_err;
 mod log_err;
 mod map_expect;
@@ -19,6 +20,7 @@ pub use self::{
 	flat_ok::FlatOk,
 	inspect_log::{ErrDebugLog, ErrLog},
 	into_is_ok::IntoIsOk,
+	is_err_or::IsErrOr,
 	log_debug_err::LogDebugErr,
 	log_err::LogErr,
 	map_expect::MapExpect,

src/core/utils/result/is_err_or.rs

@@ -0,0 +1,17 @@
+#![allow(clippy::wrong_self_convention)]
+
+use super::Result;
+
+pub trait IsErrOr<T> {
+	fn is_err_or<F: FnOnce(T) -> bool>(self, f: F) -> bool;
+}
+
+impl<T, E> IsErrOr<T> for Result<T, E> {
+	#[inline]
+	fn is_err_or<F>(self, f: F) -> bool
+	where
+		F: FnOnce(T) -> bool,
+	{
+		if let Ok(t) = self { f(t) } else { true }
+	}
+}