Tweak context, add some accessors for context, use match instead of map_err/ok_or_else

src/explain.rs

@@ -25,17 +25,17 @@ where
     }
 }
 
-impl<T> Explain for Option<T>
+impl<T> Explain for Option<T> {
-where
+    type Output = Result<T, How>;
-    Option<T>: IntoResultHow,
-{
-    type Output = Result<<Self as IntoResultHow>::T, How>;
 
     #[inline(always)]
     #[track_caller]
     fn context(self, context: impl IntoContext) -> Self::Output {
-        // TODO: maybe add a toggle for the extra "Option::None" context
+        // TODO: maybe add a feature for the extra "Option::None" context
-        //Err(How::new(context))
+        match self {
-        self.into_result_how().map_err(#[inline(never)] move |e| e.context(context))
+            Some(t) => Ok(t),
-}
+            None => Err(How::new(context))
+        }
+        //self.into_result_how().map_err(#[inline(never)] move |e| e.context(context))
     }
+}

src/how.rs

@@ -56,6 +56,46 @@ impl How {
         self.0.classified
     }
 
+    pub fn location(&self) -> &Context {
+        // SAFETY: we only ever push values into context, and the constructor ensures that there
+        // are at least 2 values in context.
+        let o = self.0.context.get(0);
+        if cfg!(debug_assertions) {
+            o.unwrap()
+        } else {
+            #[allow(unsafe_code)]
+            unsafe { o.unwrap_unchecked() }
+        }
+    }
+
+    pub fn top(&self) -> &Context {
+        // SAFETY: we only ever push values into context, and the constructor ensures that there
+        // are at least 2 values in context.
+        let o = self.0.context.get(1);
+        if cfg!(debug_assertions) {
+            o.unwrap()
+        } else {
+            #[allow(unsafe_code)]
+            unsafe { o.unwrap_unchecked() }
+        }
+    }
+
+    pub fn bottom(&self) -> &Context {
+        // SAFETY: we only ever push values into context, and the constructor ensures that there
+        // are at least 2 values in context.
+        let o = self.0.context.iter().next_back();
+        if cfg!(debug_assertions) {
+            o.unwrap()
+        } else {
+            #[allow(unsafe_code)]
+            unsafe { o.unwrap_unchecked() }
+        }
+    }
+
+    pub fn into_context(self) -> impl Iterator<Item = Context> {
+        self.0.context.into_iter()
+    }
+
     fn fmt_debug_alternate(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         let mut b = f.debug_struct(std::any::type_name::<Self>());
         let b = b

src/into.rs

@@ -27,7 +27,10 @@ where
         fn into<E: std::error::Error>(e: E) -> How {
             How::new(e.to_string())
         }
-        self.map_err(into)
+        match self {
+            Ok(t) => Ok(t),
+            Err(e) => Err(into(e))
+        }
     }
 }
 
@@ -51,6 +54,9 @@ impl<T> IntoResultHow for Option<T> {
         fn into() -> How {
             How::new("Option::None")
         }
-        self.ok_or_else(into)
+        match self {
+            Some(t) => Ok(t),
+            None => Err(into())
+        }
     }
 }

src/lib.rs

@@ -1,5 +1,5 @@
 #![doc = include_str!("../README.md")]
-#![forbid(unsafe_code)]
+#![deny(unsafe_code)]
 #![feature(backtrace)]
 
 mod sealed;