diff --git a/src/LineRef.h b/src/LineRef.h
index f887dc1..d83af37 100644
--- a/src/LineRef.h
+++ b/src/LineRef.h
@@ -1,89 +1,90 @@
 /*
  * KDiff3 - Text Diff And Merge Tool
  *
  * SPDX-FileCopyrightText: 2018-2020 Michael Reeves reeves.87@gmail.com
  * SPDX-License-Identifier: GPL-2.0-or-later
 */
 #ifndef LINEREF_H
 #define LINEREF_H
 
 #include "TypeUtils.h"
 
 #include <stdlib.h>
 #include <type_traits>
 
 #include <QtGlobal>
 
 class LineRef
 {
   public:
     typedef qint32 LineType;
-    inline LineRef() = default;
-    inline LineRef(const LineType i) { mLineNumber = i; }
-    inline LineRef(const qint64 i)
+    inline LineRef() noexcept = default;
+    inline LineRef(const LineType i) noexcept { mLineNumber = i; }
+    inline LineRef(const qint64 i) noexcept
     {
         if(i <= TYPE_MAX(LineType))
             mLineNumber = (LineType)i;
         else
             mLineNumber = -1;
     }
-    inline operator LineType() const { return mLineNumber; }
-    inline LineRef& operator=(const LineType lineIn) {
+    inline operator LineType() const noexcept { return mLineNumber; }
+    inline LineRef& operator=(const LineType lineIn) noexcept
+    {
         mLineNumber = lineIn;
         return *this;
     }
     inline LineRef& operator+=(const LineType& inLine)
     {
         mLineNumber += inLine;
         return *this;
     };
 
     LineRef& operator++()
     {
         ++mLineNumber;
         return *this;
     };
 
     const LineRef operator++(int)
     {
         LineRef line(*this);
         ++mLineNumber;
         return line;
     };
 
     LineRef& operator--()
     {
         --mLineNumber;
         return *this;
     };
 
     const LineRef operator--(int)
     {
         LineRef line(*this);
         --mLineNumber;
         return line;
     };
-    inline void invalidate() { mLineNumber = -1; }
-    inline bool isValid() const { return mLineNumber != -1; }
+    inline void invalidate() noexcept { mLineNumber = -1; }
+    inline bool isValid() const noexcept { return mLineNumber != -1; }
 
   private:
     LineType mLineNumber = -1;
 };
 
 /*
     This is here because its easy to unknowingly break these conditions. The resulting
     compiler errors are a bit cryptic if you aren't famialar with the C++ language.
     Also some IDEs with clangd or ccls integration can automatically check static_asserts
     without doing a full compile.
 */
 static_assert(std::is_copy_constructible<LineRef>::value, "LineRef must be copy constuctible.");
 static_assert(std::is_copy_assignable<LineRef>::value, "LineRef must copy assignable.");
 static_assert(std::is_move_constructible<LineRef>::value, "LineRef must be move constructible.");
 static_assert(std::is_move_assignable<LineRef>::value, "LineRef must be move assignable.");
 static_assert(std::is_convertible<LineRef, int>::value, "Can not convert LineRef to int.");
 static_assert(std::is_convertible<int, LineRef>::value, "Can not convert int to LineRef.");
 
 typedef LineRef::LineType LineCount;
 typedef LineRef::LineType LineIndex;
 
 #endif