diff --git a/toml/comments.hpp b/toml/comments.hpp
index ec25041..c0f66f3 100644
--- a/toml/comments.hpp
+++ b/toml/comments.hpp
@@ -425,14 +425,14 @@ struct discard_comments
     // empty, so accessing through operator[], front/back, data causes address
     // error.
 
-    reference       operator[](const size_type)       noexcept {return *data();}
-    const_reference operator[](const size_type) const noexcept {return *data();}
+    reference       operator[](const size_type)       noexcept {never_call("toml::discard_comment::operator[]");}
+    const_reference operator[](const size_type) const noexcept {never_call("toml::discard_comment::operator[]");}
     reference       at(const size_type)       {throw std::out_of_range("toml::discard_comment is always empty.");}
     const_reference at(const size_type) const {throw std::out_of_range("toml::discard_comment is always empty.");}
-    reference       front()       noexcept {return *data();}
-    const_reference front() const noexcept {return *data();}
-    reference       back()        noexcept {return *data();}
-    const_reference back()  const noexcept {return *data();}
+    reference       front()       noexcept {never_call("toml::discard_comment::front");}
+    const_reference front() const noexcept {never_call("toml::discard_comment::front");}
+    reference       back()        noexcept {never_call("toml::discard_comment::back");}
+    const_reference back()  const noexcept {never_call("toml::discard_comment::back");}
 
     pointer         data()        noexcept {return nullptr;}
     const_pointer   data()  const noexcept {return nullptr;}
@@ -450,6 +450,18 @@ struct discard_comments
     const_reverse_iterator rend()    const noexcept {return const_iterator{};}
     const_reverse_iterator crbegin() const noexcept {return const_iterator{};}
     const_reverse_iterator crend()   const noexcept {return const_iterator{};}
+
+  private:
+
+    [[noreturn]] static void never_call(const char *const this_function)
+    {
+#ifdef __has_builtin
+#  if __has_builtin(__builtin_unreachable)
+        __builtin_unreachable();
+#  endif
+#endif
+        throw std::logic_error{this_function};
+    }
 };
 
 inline bool operator==(const discard_comments&, const discard_comments&) noexcept {return true;}