Infallible errors

https://doc.rust-lang.org/std/convert/enum.Infallible.html

src/error.rs

@@ -210,3 +210,13 @@ impl From<::strum::ParseError> for Error {
         Error::custom(value) // TODO!
     }
 }
+
+impl From<String> for Error {
+    fn from(value: String) -> Self { Error::custom(value) }
+}
+
+impl From<::core::convert::Infallible> for Error {
+    fn from(_: ::core::convert::Infallible) -> Self {
+        Error::custom("An Infallible error has been returned! (this should never happen!)")
+    }
+}

src/master_playlist.rs

@@ -17,7 +17,6 @@ use crate::{Error, RequiredVersion};
 #[builder(setter(into, strip_option))]
 /// Master playlist.
 pub struct MasterPlaylist {
-    //#[builder(default, setter(name = "version"))]
     #[builder(default, setter(skip))]
     version_tag: ExtXVersion,
     #[builder(default)]

src/types/closed_captions.rs

@@ -1,8 +1,8 @@
+use core::convert::Infallible;
 use std::fmt;
 use std::str::FromStr;
 
 use crate::utils::{quote, unquote};
-use crate::Error;
 
 /// The identifier of a closed captions group or its absence.
 ///
@@ -26,7 +26,7 @@ impl fmt::Display for ClosedCaptions {
 }
 
 impl FromStr for ClosedCaptions {
-    type Err = Error;
+    type Err = Infallible;
 
     fn from_str(input: &str) -> Result<Self, Self::Err> {
         if input.trim() == "NONE" {

src/types/key_format_versions.rs

@@ -1,10 +1,11 @@
+use std::convert::Infallible;
 use std::fmt;
 use std::ops::{Deref, DerefMut};
 use std::str::FromStr;
 
 use crate::types::ProtocolVersion;
 use crate::utils::{quote, unquote};
-use crate::{Error, RequiredVersion};
+use crate::RequiredVersion;
 
 /// A list of [usize], that can be used to indicate which version(s)
 /// this instance complies with, if more than one version of a particular
@@ -51,7 +52,7 @@ impl RequiredVersion for KeyFormatVersions {
 }
 
 impl FromStr for KeyFormatVersions {
-    type Err = Error;
+    type Err = Infallible;
 
     fn from_str(input: &str) -> Result<Self, Self::Err> {
         let mut result = unquote(input)