view: add trim_if

view.hpp

@@ -727,6 +727,29 @@ namespace cruft {
     }
 
 
+    ///////////////////////////////////////////////////////////////////////////
+    template <typename BeginT, typename EndT, typename FunctionT>
+    view<BeginT, EndT>
+    trim_if [[nodiscard]] (
+        view<BeginT, EndT> const buffer,
+        FunctionT &&test
+    ) {
+        auto const first = std::find_if_not (
+            std::begin (buffer),
+            std::end   (buffer),
+            test
+        );
+
+        auto const last = std::find_if_not (
+            std::make_reverse_iterator (buffer.end ()),
+            std::make_reverse_iterator (first),
+            test
+        );
+
+        return view (first, last.base ());
+    }
+
+
     ///////////////////////////////////////////////////////////////////////////
     /// Returns a reference to a value of the designated type at the front of
     /// the word-view. if there is insufficient data for the extraction an