diff --git a/yaml-path/yaml-path-internals.h b/yaml-path/yaml-path-internals.h
index b880f91..8ee3377 100644
--- a/yaml-path/yaml-path-internals.h
+++ b/yaml-path/yaml-path-internals.h
@@ -212,7 +212,7 @@ namespace YAML
       template <typename TBits, typename T>
       constexpr uint64_t BitsOf(std::initializer_list<T> values)
       {
-         __int64 bits = 0;
+         int64_t bits = 0;
          for (auto v : values)
             bits |= TBits(1) << TBits(v);
          return bits;
diff --git a/yaml-path/yaml-path.cpp b/yaml-path/yaml-path.cpp
index 677214b..734df01 100644
--- a/yaml-path/yaml-path.cpp
+++ b/yaml-path/yaml-path.cpp
@@ -26,6 +26,9 @@ SOFTWARE.
 #include "yaml-path-internals.h"
 #include <yaml-cpp/yaml.h>
 #include <assert.h>
+#include <algorithm>
+#include <cstring>
+#include <strings.h>
 
 /// namspace shared by yaml-cpp and yaml-path
 namespace YAML
@@ -82,6 +85,15 @@ namespace YAML
 
    namespace YamlPathDetail
    {
+      /// \internal result = target; target = newValue
+      template <typename T1, typename T2>
+      T1 Exchange(T1 & target, T2 newValue)
+      {
+         T1 result = std::move(target);
+         target = std::move(newValue);
+         return std::move(result);
+      }
+
       /// \internal uses the same mapping as \ref MapValue to create diagnostic for a bit mask (e.g. created by \ref BitsOf)
       template <typename T2, typename TBit, typename TMask>
       std::string MapBitMask(TMask value, std::initializer_list<std::pair<TBit, T2>> values, T2 sep = ", ")
@@ -166,15 +178,6 @@ namespace YAML
          return undefinedNode;
       }
 
-      /// \internal result = target; target = newValue
-      template <typename T1, typename T2>
-      T1 Exchange(T1 & target, T2 newValue)
-      {
-         T1 result = std::move(target);
-         target = std::move(newValue);
-         return std::move(result);
-      }
-
 
       /** \internal splits path at offset, 
           returning everything left of [offset], assigning everything right of it to \c path. 
@@ -681,7 +684,7 @@ namespace YAML
 
          // Unicode: some assumptions here don't hold. It's strcoll, stricoll, and I'm not sure how to implement no-case starry matches
          size_t cmpLen = std::min(tok.token.length(), snode.length());
-         int result = tok.noCase ? _strnicmp(&tok.token[0], snode.c_str(), cmpLen) : strncmp(&tok.token[0], snode.c_str(), cmpLen);
+         int result = tok.noCase ? strncasecmp(&tok.token[0], snode.c_str(), cmpLen) : strncmp(&tok.token[0], snode.c_str(), cmpLen);
 
          return result == 0; // under assumption of above length-based shortcuts
       }
@@ -923,22 +926,21 @@ namespace YAML
 
    namespace YamlPathDetail
    {
-      Node EnsureNodeApplyKeyToMapOrNothing(Node & start, std::string key)
+      Node EnsureNodeApplyKeyToMapOrNothing(const Node & start, std::string key)
       {
          Node n = start[key];
          if (n)
             return n;
-         start[key] = Node(NodeType::Null);
-         return start[key];
+         return Node(NodeType::Null);
       }
 
-      void EnsureNodeApplyKey(std::vector<Node> & result, Node & start, std::string key, bool recurse)
+      void EnsureNodeApplyKey(std::vector<Node> & result, const Node & start, std::string key, bool recurse)
       {
          if (!start || start.IsNull() || start.IsMap())
             result.push_back(EnsureNodeApplyKeyToMapOrNothing(start, key));
          else if (start.IsSequence() && recurse)
          {
-            for (auto & el : start)
+            for (auto& el : start)
                if (el.IsNull() || el.IsMap())
                   EnsureNodeApplyKey(result, el, key, false);
          }
@@ -946,7 +948,7 @@ namespace YAML
 
       void EnsureNodeApplyKey(std::vector<Node> & result, std::vector<Node> & start, std::string key)
       {
-         for (auto & el : start)
+         for (auto& el : start)
             if (el.IsNull() || el.IsMap())
                EnsureNodeApplyKey(result, el, key, true);
       }
diff --git a/yaml-path/yaml-path.h b/yaml-path/yaml-path.h
index 567f593..e80b1ae 100644
--- a/yaml-path/yaml-path.h
+++ b/yaml-path/yaml-path.h
@@ -112,7 +112,7 @@ namespace YAML
       std::size_t ErrorOffset() const { return m_offsTokenScan; }                            ///< index into the full path where the error occurred
       std::optional<size_t> BoundArg() const { return m_fromBoundArg;  }                     ///< if token was taken from a bound argument, this is its index
 
-      char const * what() const override { return What().c_str(); }                          ///< overrides \c std::exception::what, returning the detailed error message from \ref What
+      char const * what() const noexcept override { return What().c_str(); }                          ///< overrides \c std::exception::what, returning the detailed error message from \ref What
       std::string const & What(bool detailed = true) const;                
 
       static std::string GetErrorMessage(EPathError error);