diff --git a/src/Parser/Parsing/ILexer.h b/src/Parser/Parsing/ILexer.h
index e0a53c3c..9542574e 100644
--- a/src/Parser/Parsing/ILexer.h
+++ b/src/Parser/Parsing/ILexer.h
@@ -3,11 +3,10 @@
 #include "IParserLineStream.h"
 #include "Parsing/IParserValue.h"
 
-template<typename TokenType> class ILexer
-{
-    // TokenType must inherit IParserValue
-    static_assert(std::is_base_of<IParserValue, TokenType>::value);
+#include <concepts>
 
+template<std::derived_from<IParserValue> TokenType> class ILexer
+{
 public:
     ILexer() = default;
     virtual ~ILexer() = default;
@@ -16,10 +15,10 @@ public:
     ILexer& operator=(const ILexer& other) = default;
     ILexer& operator=(ILexer&& other) noexcept = default;
 
-    virtual const TokenType& GetToken(unsigned index) = 0;
-    virtual void PopTokens(int amount) = 0;
+    virtual const TokenType& GetToken(size_t index) = 0;
+    virtual void PopTokens(size_t amount) = 0;
 
-    _NODISCARD virtual bool IsEof() = 0;
-    _NODISCARD virtual const TokenPos& GetPos() = 0;
-    _NODISCARD virtual ParserLine GetLineForPos(const TokenPos& pos) const = 0;
+    [[nodiscard]] virtual bool IsEof() = 0;
+    [[nodiscard]] virtual const TokenPos& GetPos() = 0;
+    [[nodiscard]] virtual ParserLine GetLineForPos(const TokenPos& pos) const = 0;
 };
diff --git a/src/Parser/Parsing/Impl/AbstractLexer.h b/src/Parser/Parsing/Impl/AbstractLexer.h
index 637be807..34b6f2dd 100644
--- a/src/Parser/Parsing/Impl/AbstractLexer.h
+++ b/src/Parser/Parsing/Impl/AbstractLexer.h
@@ -7,21 +7,82 @@
 #include "Utils/StringUtils.h"
 
 #include <cassert>
+#include <concepts>
 #include <deque>
 #include <sstream>
 
-template<typename TokenType> class AbstractLexer : public ILexer<TokenType>
+template<std::derived_from<IParserValue> TokenType> class AbstractLexer : public ILexer<TokenType>
 {
-    // TokenType must inherit IParserValue
-    static_assert(std::is_base_of<IParserValue, TokenType>::value);
+public:
+    const TokenType& GetToken(const size_t index) override
+    {
+        while (index >= m_token_cache.size())
+            m_token_cache.emplace_back(GetNextToken());
+
+        return m_token_cache[index];
+    }
+
+    void PopTokens(size_t amount) override
+    {
+        if (amount == 0 || m_token_cache.empty())
+            return;
+
+        if (m_token_cache.size() <= amount)
+        {
+            const auto& lastToken = m_token_cache.back();
+            while (
+                !m_line_cache.empty()
+                && (m_line_cache.front().m_line_number != lastToken.GetPos().m_line || *m_line_cache.front().m_filename != lastToken.GetPos().m_filename.get()))
+            {
+                m_line_cache.pop_front();
+                m_line_index--;
+            }
+            m_token_cache.clear();
+        }
+        else
+        {
+            m_token_cache.erase(m_token_cache.begin(), m_token_cache.begin() + amount);
+            const auto& firstToken = m_token_cache.front();
+            while (!m_line_cache.empty()
+                   && (m_line_cache.front().m_line_number != firstToken.GetPos().m_line
+                       || *m_line_cache.front().m_filename != firstToken.GetPos().m_filename.get()))
+            {
+                m_line_cache.pop_front();
+                m_line_index--;
+            }
+        }
+    }
+
+    [[nodiscard]] bool IsEof() override
+    {
+        return GetToken(0).IsEof();
+    }
+
+    [[nodiscard]] const TokenPos& GetPos() override
+    {
+        return GetToken(0).GetPos();
+    }
+
+    [[nodiscard]] ParserLine GetLineForPos(const TokenPos& pos) const override
+    {
+        for (const auto& line : m_line_cache)
+        {
+            if (line.m_filename && *line.m_filename == pos.m_filename.get() && line.m_line_number == pos.m_line)
+            {
+                return line;
+            }
+        }
+
+        return ParserLine();
+    }
 
 protected:
     std::deque<TokenType> m_token_cache;
     std::deque<ParserLine> m_line_cache;
-    IParserLineStream* const m_stream;
+    IParserLineStream* m_stream;
 
-    unsigned m_line_index;
-    unsigned m_current_line_offset;
+    size_t m_line_index;
+    size_t m_current_line_offset;
 
     explicit AbstractLexer(IParserLineStream* stream)
         : m_stream(stream),
@@ -83,28 +144,28 @@ protected:
         return m_line_cache[peekLine].m_line[peekLineOffset];
     }
 
-    _NODISCARD const ParserLine& CurrentLine() const
+    [[nodiscard]] const ParserLine& CurrentLine() const
     {
         return m_line_cache[m_line_index];
     }
 
-    _NODISCARD bool IsLineEnd() const
+    [[nodiscard]] bool IsLineEnd() const
     {
         return m_current_line_offset >= CurrentLine().m_line.size();
     }
 
-    _NODISCARD bool NextCharInLineIs(const char c)
+    [[nodiscard]] bool NextCharInLineIs(const char c)
     {
         return !IsLineEnd() && PeekChar() == c;
     }
 
-    _NODISCARD TokenPos GetPreviousCharacterPos() const
+    [[nodiscard]] TokenPos GetPreviousCharacterPos() const
     {
         const auto& currentLine = CurrentLine();
         return TokenPos(*currentLine.m_filename, currentLine.m_line_number, m_current_line_offset);
     }
 
-    _NODISCARD TokenPos GetNextCharacterPos()
+    [[nodiscard]] TokenPos GetNextCharacterPos()
     {
         const auto& currentLine = CurrentLine();
         if (m_current_line_offset + 1 >= currentLine.m_line.size())
@@ -227,7 +288,7 @@ protected:
         m_current_line_offset += numberLength - 1;
     }
 
-    _NODISCARD bool IsIntegerNumber() const
+    [[nodiscard]] bool IsIntegerNumber() const
     {
         const auto& currentLine = CurrentLine();
         const auto* currentCharacter = &currentLine.m_line.c_str()[m_current_line_offset - 1];
@@ -350,67 +411,4 @@ protected:
             integerValue = ReadInteger();
         }
     }
-
-public:
-    const TokenType& GetToken(unsigned index) override
-    {
-        while (index >= m_token_cache.size())
-            m_token_cache.emplace_back(GetNextToken());
-
-        return m_token_cache[index];
-    }
-
-    void PopTokens(int amount) override
-    {
-        if (amount <= 0 || m_token_cache.empty())
-            return;
-
-        if (static_cast<int>(m_token_cache.size()) <= amount)
-        {
-            const auto& lastToken = m_token_cache.back();
-            while (
-                !m_line_cache.empty()
-                && (m_line_cache.front().m_line_number != lastToken.GetPos().m_line || *m_line_cache.front().m_filename != lastToken.GetPos().m_filename.get()))
-            {
-                m_line_cache.pop_front();
-                m_line_index--;
-            }
-            m_token_cache.clear();
-        }
-        else
-        {
-            m_token_cache.erase(m_token_cache.begin(), m_token_cache.begin() + amount);
-            const auto& firstToken = m_token_cache.front();
-            while (!m_line_cache.empty()
-                   && (m_line_cache.front().m_line_number != firstToken.GetPos().m_line
-                       || *m_line_cache.front().m_filename != firstToken.GetPos().m_filename.get()))
-            {
-                m_line_cache.pop_front();
-                m_line_index--;
-            }
-        }
-    }
-
-    _NODISCARD bool IsEof() override
-    {
-        return GetToken(0).IsEof();
-    }
-
-    _NODISCARD const TokenPos& GetPos() override
-    {
-        return GetToken(0).GetPos();
-    }
-
-    _NODISCARD ParserLine GetLineForPos(const TokenPos& pos) const override
-    {
-        for (const auto& line : m_line_cache)
-        {
-            if (line.m_filename && *line.m_filename == pos.m_filename.get() && line.m_line_number == pos.m_line)
-            {
-                return line;
-            }
-        }
-
-        return ParserLine();
-    }
 };
diff --git a/src/Parser/Parsing/Impl/DefinesStreamProxy.cpp b/src/Parser/Parsing/Impl/DefinesStreamProxy.cpp
index 38e80040..9c241627 100644
--- a/src/Parser/Parsing/Impl/DefinesStreamProxy.cpp
+++ b/src/Parser/Parsing/Impl/DefinesStreamProxy.cpp
@@ -5,7 +5,6 @@
 #include "Parsing/Simple/Expression/ISimpleExpression.h"
 #include "Parsing/Simple/Expression/SimpleExpressionMatchers.h"
 #include "Parsing/Simple/SimpleExpressionInterpreter.h"
-#include "Utils/ClassUtils.h"
 #include "Utils/StringUtils.h"
 
 #include <regex>
@@ -114,7 +113,7 @@ void DefinesStreamProxy::Define::IdentifyParameters(const std::vector<std::strin
                 {
                     m_contains_token_pasting_operators = true;
 
-                    // Skip next char since it's # anyway and we do not want to count it as stringize
+                    // Skip next char since it's # anyway, and we do not want to count it as stringize
                     i++;
                 }
             }
@@ -484,7 +483,7 @@ bool DefinesStreamProxy::MatchEndifDirective(const ParserLine& line, const size_
     return true;
 }
 
-bool DefinesStreamProxy::MatchDirectives(ParserLine& line)
+bool DefinesStreamProxy::MatchDirectives(const ParserLine& line)
 {
     size_t directiveStartPos;
     size_t directiveEndPos;
@@ -522,7 +521,7 @@ bool DefinesStreamProxy::FindMacroForIdentifier(const std::string& input,
 }
 
 void DefinesStreamProxy::ExtractParametersFromMacroUsage(
-    const ParserLine& line, unsigned& linePos, MacroParameterState& state, const std::string& input, unsigned& inputPos)
+    const ParserLine& line, const unsigned& linePos, MacroParameterState& state, const std::string& input, unsigned& inputPos)
 {
     if (input[inputPos] != '(')
         return;
@@ -588,7 +587,7 @@ void DefinesStreamProxy::ExpandDefinedExpressions(ParserLine& line) const
     }
 }
 
-bool DefinesStreamProxy::FindNextMacro(const std::string& input, unsigned& inputPos, unsigned& defineStart, const DefinesStreamProxy::Define*& define)
+bool DefinesStreamProxy::FindNextMacro(const std::string& input, unsigned& inputPos, unsigned& defineStart, const Define*& define) const
 {
     const auto inputSize = input.size();
     auto wordStart = 0u;
@@ -655,7 +654,7 @@ bool DefinesStreamProxy::FindNextMacro(const std::string& input, unsigned& input
 
 namespace
 {
-    enum class TokenPasteTokenType
+    enum class TokenPasteTokenType : std::uint8_t
     {
         NONE,
         STRING,
@@ -673,13 +672,7 @@ namespace
         {
         }
 
-        ~TokenPasteToken() = default;
-        TokenPasteToken(const TokenPasteToken& other) = default;
-        TokenPasteToken(TokenPasteToken&& other) = default;
-        TokenPasteToken& operator=(const TokenPasteToken& other) = default;
-        TokenPasteToken& operator=(TokenPasteToken&& other) noexcept = default;
-
-        void SetFromInput(ParserLine& line, unsigned& linePos, const std::string& input, unsigned& offset)
+        void SetFromInput(const ParserLine& line, const unsigned& linePos, const std::string& input, unsigned& offset)
         {
             m_start = offset;
 
@@ -698,8 +691,8 @@ namespace
                 }
 
                 if (offset >= inputSize)
-                    throw new ParsingException(TokenPos(*line.m_filename, line.m_line_number, static_cast<int>(linePos + 1)),
-                                               "Token-pasting operator cannot be used on unclosed string");
+                    throw ParsingException(TokenPos(*line.m_filename, line.m_line_number, static_cast<int>(linePos + 1)),
+                                           "Token-pasting operator cannot be used on unclosed string");
 
                 offset++;
             }
@@ -743,12 +736,16 @@ namespace
         unsigned m_end;
     };
 
-    void EmitPastedTokens(
-        ParserLine& line, unsigned& linePos, std::ostream& out, const std::string& input, const TokenPasteToken& token0, const TokenPasteToken& token1)
+    void EmitPastedTokens(const ParserLine& line,
+                          const unsigned& linePos,
+                          std::ostream& out,
+                          const std::string& input,
+                          const TokenPasteToken& token0,
+                          const TokenPasteToken& token1)
     {
         if ((token0.m_type == TokenPasteTokenType::STRING) != (token1.m_type == TokenPasteTokenType::STRING))
-            throw new ParsingException(TokenPos(*line.m_filename, line.m_line_number, static_cast<int>(linePos + 1)),
-                                       "String token can only use token-pasting operator on other string token");
+            throw ParsingException(TokenPos(*line.m_filename, line.m_line_number, static_cast<int>(linePos + 1)),
+                                   "String token can only use token-pasting operator on other string token");
         if (token0.m_type == TokenPasteTokenType::STRING)
         {
             out << '"';
@@ -767,7 +764,7 @@ namespace
 } // namespace
 
 void DefinesStreamProxy::ProcessTokenPastingOperators(
-    ParserLine& line, unsigned& linePos, std::vector<const Define*>& callstack, std::string& input, unsigned& inputPos)
+    const ParserLine& line, const unsigned& linePos, std::vector<const Define*>& callstack, std::string& input, unsigned& inputPos)
 {
     std::ostringstream ss;
 
@@ -789,7 +786,7 @@ void DefinesStreamProxy::ProcessTokenPastingOperators(
         if (c == '#' && IsTokenPastingOperatorForwardLookup(input, i))
         {
             if (currentToken.m_type == TokenPasteTokenType::NONE)
-                throw new ParsingException(CreatePos(line, linePos), "Cannot use token-pasting operator without previous token");
+                throw ParsingException(CreatePos(line, linePos), "Cannot use token-pasting operator without previous token");
 
             if (previousToken.m_end < currentToken.m_start)
                 ss << std::string(input, previousToken.m_end, currentToken.m_start - previousToken.m_end);
@@ -816,12 +813,12 @@ void DefinesStreamProxy::ProcessTokenPastingOperators(
         ss << std::string(input, previousToken.m_end, inputSize - previousToken.m_end);
 
     if (pasteNext)
-        throw new ParsingException(CreatePos(line, linePos), "Cannot use token-pasting operator without following token");
+        throw ParsingException(CreatePos(line, linePos), "Cannot use token-pasting operator without following token");
 
     input = ss.str();
 }
 
-void DefinesStreamProxy::InsertMacroParameters(std::ostringstream& out, const DefinesStreamProxy::Define* macro, std::vector<std::string>& parameterValues)
+void DefinesStreamProxy::InsertMacroParameters(std::ostringstream& out, const Define* macro, const std::vector<std::string>& parameterValues)
 {
     if (parameterValues.empty() || macro->m_parameter_positions.empty())
     {
@@ -829,7 +826,7 @@ void DefinesStreamProxy::InsertMacroParameters(std::ostringstream& out, const De
         return;
     }
 
-    auto lastPos = 0u;
+    auto lastPos = 0uz;
     for (const auto& parameterPosition : macro->m_parameter_positions)
     {
         if (lastPos < parameterPosition.m_parameter_position)
@@ -857,7 +854,7 @@ void DefinesStreamProxy::ExpandMacro(ParserLine& line,
                                      std::ostringstream& out,
                                      std::vector<const Define*>& callstack,
                                      const DefinesStreamProxy::Define* macro,
-                                     std::vector<std::string>& parameterValues)
+                                     const std::vector<std::string>& parameterValues)
 {
     std::ostringstream rawOutput;
     InsertMacroParameters(rawOutput, macro, parameterValues);
@@ -873,7 +870,7 @@ void DefinesStreamProxy::ExpandMacro(ParserLine& line,
 }
 
 void DefinesStreamProxy::ContinueMacroParameters(
-    const ParserLine& line, unsigned& linePos, MacroParameterState& state, const std::string& input, unsigned& inputPos)
+    const ParserLine& line, const unsigned& linePos, MacroParameterState& state, const std::string& input, unsigned& inputPos)
 {
     const auto inputLength = input.size();
     while (state.m_parameter_state != ParameterState::NOT_IN_PARAMETERS && inputPos < inputLength)
diff --git a/src/Parser/Parsing/Impl/DefinesStreamProxy.h b/src/Parser/Parsing/Impl/DefinesStreamProxy.h
index 28d8564a..d9beffb6 100644
--- a/src/Parser/Parsing/Impl/DefinesStreamProxy.h
+++ b/src/Parser/Parsing/Impl/DefinesStreamProxy.h
@@ -107,26 +107,29 @@ private:
     _NODISCARD bool MatchIfdefDirective(const ParserLine& line, size_t directiveStartPosition, size_t directiveEndPosition);
     _NODISCARD bool MatchElseDirective(const ParserLine& line, size_t directiveStartPosition, size_t directiveEndPosition);
     _NODISCARD bool MatchEndifDirective(const ParserLine& line, size_t directiveStartPosition, size_t directiveEndPosition);
-    _NODISCARD bool MatchDirectives(ParserLine& line);
+    _NODISCARD bool MatchDirectives(const ParserLine& line);
 
-    void ExtractParametersFromMacroUsage(const ParserLine& line, unsigned& linePos, MacroParameterState& state, const std::string& input, unsigned& inputPos);
-    bool FindMacroForIdentifier(const std::string& input, unsigned wordStart, unsigned wordEnd, const Define*& value) const;
+    static void ExtractParametersFromMacroUsage(
+        const ParserLine& line, const unsigned& linePos, MacroParameterState& state, const std::string& input, unsigned& inputPos);
+    bool FindMacroForIdentifier(const std::string& input, unsigned identifierStart, unsigned identifierEnd, const Define*& value) const;
 
     static bool MatchDefinedExpression(const ParserLine& line, size_t& pos, std::string& definitionName);
     void ExpandDefinedExpressions(ParserLine& line) const;
 
-    bool FindNextMacro(const std::string& input, unsigned& inputPos, unsigned& defineStart, const DefinesStreamProxy::Define*& define);
+    bool FindNextMacro(const std::string& input, unsigned& inputPos, unsigned& defineStart, const DefinesStreamProxy::Define*& define) const;
 
-    void ProcessTokenPastingOperators(ParserLine& line, unsigned& linePos, std::vector<const Define*>& callstack, std::string& input, unsigned& inputPos);
-    void InsertMacroParameters(std::ostringstream& out, const DefinesStreamProxy::Define* macro, std::vector<std::string>& parameterValues);
+    static void ProcessTokenPastingOperators(
+        const ParserLine& line, const unsigned& linePos, std::vector<const Define*>& callstack, std::string& input, unsigned& inputPos);
+    static void InsertMacroParameters(std::ostringstream& out, const DefinesStreamProxy::Define* macro, const std::vector<std::string>& parameterValues);
     void ExpandMacro(ParserLine& line,
                      unsigned& linePos,
                      std::ostringstream& out,
                      std::vector<const Define*>& callstack,
                      const DefinesStreamProxy::Define* macro,
-                     std::vector<std::string>& parameterValues);
+                     const std::vector<std::string>& parameterValues);
 
-    void ContinueMacroParameters(const ParserLine& line, unsigned& linePos, MacroParameterState& state, const std::string& input, unsigned& inputPos);
+    static void
+        ContinueMacroParameters(const ParserLine& line, const unsigned& linePos, MacroParameterState& state, const std::string& input, unsigned& inputPos);
     void ContinueMultiLineMacro(ParserLine& line);
 
     void ProcessNestedMacros(ParserLine& line, unsigned& linePos, std::vector<const Define*>& callstack, std::string& input, unsigned& inputPos);
diff --git a/src/Parser/Parsing/Matcher/MatcherResult.cpp b/src/Parser/Parsing/Matcher/MatcherResult.cpp
new file mode 100644
index 00000000..b79de9ce
--- /dev/null
+++ b/src/Parser/Parsing/Matcher/MatcherResult.cpp
@@ -0,0 +1,47 @@
+#include "MatcherResult.h"
+
+namespace
+{
+    // The highest bit is the fabricated flag
+    constexpr size_t FABRICATED_FLAG_MASK = 1uz << (sizeof(size_t) * 8uz - 1uz);
+    constexpr size_t TOKEN_INDEX_MASK = ~FABRICATED_FLAG_MASK;
+} // namespace
+
+MatcherResultTokenIndex::MatcherResultTokenIndex(const size_t index, const bool isFabricated)
+{
+    m_token_index = index & TOKEN_INDEX_MASK;
+    if (isFabricated)
+        m_token_index |= FABRICATED_FLAG_MASK;
+}
+
+bool MatcherResultTokenIndex::IsFabricated() const
+{
+    return m_token_index & FABRICATED_FLAG_MASK;
+}
+
+size_t MatcherResultTokenIndex::GetTokenIndex() const
+{
+    return m_token_index & TOKEN_INDEX_MASK;
+}
+
+MatcherResultCapture::MatcherResultCapture(const int captureId, const unsigned tokenIndex)
+    : MatcherResultCapture(captureId, tokenIndex, false)
+{
+}
+
+MatcherResultCapture::MatcherResultCapture(const int captureId, const unsigned tokenIndex, const bool isFabricated)
+    : m_capture_id(captureId),
+      m_token_index(tokenIndex, isFabricated)
+{
+}
+
+MatcherResultCapture::MatcherResultCapture(const int captureId, const MatcherResultTokenIndex index)
+    : m_capture_id(captureId),
+      m_token_index(index)
+{
+}
+
+int MatcherResultCapture::GetCaptureId() const
+{
+    return m_capture_id;
+}
diff --git a/src/Parser/Parsing/Matcher/MatcherResult.h b/src/Parser/Parsing/Matcher/MatcherResult.h
index f3e99e9d..719f30d5 100644
--- a/src/Parser/Parsing/Matcher/MatcherResult.h
+++ b/src/Parser/Parsing/Matcher/MatcherResult.h
@@ -1,89 +1,40 @@
 #pragma once
 
 #include "Parsing/IParserValue.h"
-#include "Utils/ClassUtils.h"
 
+#include <algorithm>
+#include <concepts>
 #include <iterator>
-#include <limits>
 #include <vector>
 
-template<typename TokenType> class MatcherResult
+class MatcherResultTokenIndex
 {
-    // TokenType must inherit IParserValue
-    static_assert(std::is_base_of<IParserValue, TokenType>::value);
-
 public:
-    class TokenIndex
-    {
-        static constexpr unsigned FABRICATED_FLAG_MASK = std::numeric_limits<unsigned>::max() ^ std::numeric_limits<int>::max();
-        static constexpr unsigned TOKEN_INDEX_MASK = ~FABRICATED_FLAG_MASK;
-
-        unsigned m_token_index;
-
-    public:
-        TokenIndex(const unsigned index, const bool isFabricated)
-        {
-            m_token_index = index & TOKEN_INDEX_MASK;
-            if (isFabricated)
-                m_token_index |= FABRICATED_FLAG_MASK;
-        }
-
-        _NODISCARD bool IsFabricated() const
-        {
-            return m_token_index & FABRICATED_FLAG_MASK;
-        }
-
-        _NODISCARD unsigned GetTokenIndex() const
-        {
-            return m_token_index & TOKEN_INDEX_MASK;
-        }
-    };
-
-    class Capture
-    {
-    public:
-        int m_capture_id;
-        TokenIndex m_token_index;
-
-        Capture(const int captureId, const unsigned tokenIndex)
-            : Capture(captureId, tokenIndex, false)
-        {
-        }
-
-        Capture(const int captureId, const unsigned tokenIndex, const bool isFabricated)
-            : m_capture_id(captureId),
-              m_token_index(tokenIndex, isFabricated)
-        {
-        }
-
-        Capture(const int captureId, const TokenIndex index)
-            : m_capture_id(captureId),
-              m_token_index(index)
-        {
-        }
-
-        _NODISCARD int GetCaptureId() const
-        {
-            return m_capture_id;
-        }
-    };
-
-    bool m_matches;
-    unsigned m_consumed_token_count;
-    std::vector<int> m_tags;
-    std::vector<Capture> m_captures;
-    std::vector<TokenIndex> m_matched_tokens;
-    std::vector<TokenType> m_fabricated_tokens;
+    MatcherResultTokenIndex(size_t index, bool isFabricated);
+    [[nodiscard]] bool IsFabricated() const;
+    [[nodiscard]] size_t GetTokenIndex() const;
 
 private:
-    MatcherResult(const bool matches, const unsigned consumedTokenCount)
-        : m_matches(matches),
-          m_consumed_token_count(consumedTokenCount)
-    {
-    }
+    size_t m_token_index;
+};
 
+class MatcherResultCapture
+{
 public:
-    static MatcherResult Match(unsigned consumedTokenCount)
+    MatcherResultCapture(int captureId, unsigned tokenIndex);
+    MatcherResultCapture(int captureId, unsigned tokenIndex, bool isFabricated);
+    MatcherResultCapture(int captureId, MatcherResultTokenIndex index);
+
+    [[nodiscard]] int GetCaptureId() const;
+
+    int m_capture_id;
+    MatcherResultTokenIndex m_token_index;
+};
+
+template<std::derived_from<IParserValue> TokenType> class MatcherResult
+{
+public:
+    static MatcherResult Match(const unsigned consumedTokenCount)
     {
         return MatcherResult(true, consumedTokenCount);
     }
@@ -98,12 +49,13 @@ public:
         m_consumed_token_count += other.m_consumed_token_count;
 
         if (!other.m_tags.empty())
-            std::copy(other.m_tags.begin(), other.m_tags.end(), std::back_inserter(m_tags));
+            std::ranges::copy(other.m_tags, std::back_inserter(m_tags));
 
         for (const auto& capture : other.m_captures)
         {
             if (capture.m_token_index.IsFabricated())
-                m_captures.emplace_back(capture.GetCaptureId(), TokenIndex(m_fabricated_tokens.size() + capture.m_token_index.GetTokenIndex(), true));
+                m_captures.emplace_back(capture.GetCaptureId(),
+                                        MatcherResultTokenIndex(m_fabricated_tokens.size() + capture.m_token_index.GetTokenIndex(), true));
             else
                 m_captures.emplace_back(capture.GetCaptureId(), capture.m_token_index);
         }
@@ -121,4 +73,18 @@ public:
             m_fabricated_tokens.emplace_back(std::move(fabricated));
         }
     }
+
+    bool m_matches;
+    unsigned m_consumed_token_count;
+    std::vector<int> m_tags;
+    std::vector<MatcherResultCapture> m_captures;
+    std::vector<MatcherResultTokenIndex> m_matched_tokens;
+    std::vector<TokenType> m_fabricated_tokens;
+
+private:
+    MatcherResult(const bool matches, const unsigned consumedTokenCount)
+        : m_matches(matches),
+          m_consumed_token_count(consumedTokenCount)
+    {
+    }
 };
diff --git a/src/Parser/Parsing/Sequence/SequenceResult.h b/src/Parser/Parsing/Sequence/SequenceResult.h
index 764e43ea..fb268bd7 100644
--- a/src/Parser/Parsing/Sequence/SequenceResult.h
+++ b/src/Parser/Parsing/Sequence/SequenceResult.h
@@ -5,9 +5,10 @@
 #include "Parsing/ParsingException.h"
 #include "Utils/ClassUtils.h"
 
+#include <concepts>
 #include <unordered_map>
 
-template<typename TokenType> class SequenceResult
+template<std::derived_from<IParserValue> TokenType> class SequenceResult
 {
     class Capture
     {
@@ -21,9 +22,6 @@ template<typename TokenType> class SequenceResult
         }
     };
 
-    // TokenType must inherit IParserValue
-    static_assert(std::is_base_of<IParserValue, TokenType>::value);
-
     std::vector<int> m_tags;
     std::unordered_map<int, Capture> m_captures;
 
@@ -34,7 +32,7 @@ public:
         : m_tags(result.m_tags),
           m_tag_offset(0)
     {
-        for (const typename MatcherResult<TokenType>::Capture& capture : result.m_captures)
+        for (const MatcherResultCapture& capture : result.m_captures)
         {
             if (capture.m_token_index.IsFabricated())
                 m_captures[capture.GetCaptureId()].m_tokens.push_back(result.m_fabricated_tokens[capture.m_token_index.GetTokenIndex()]);
diff --git a/src/Parser/Parsing/Simple/Expression/SimpleExpressionMatchers.cpp b/src/Parser/Parsing/Simple/Expression/SimpleExpressionMatchers.cpp
index a5f21c30..8a347444 100644
--- a/src/Parser/Parsing/Simple/Expression/SimpleExpressionMatchers.cpp
+++ b/src/Parser/Parsing/Simple/Expression/SimpleExpressionMatchers.cpp
@@ -7,6 +7,7 @@
 
 #include <algorithm>
 #include <list>
+#include <ranges>
 
 static constexpr int TAG_EXPRESSION = SimpleExpressionMatchers::TAG_OFFSET_EXPRESSION + 1;
 static constexpr int TAG_OPERAND = SimpleExpressionMatchers::TAG_OFFSET_EXPRESSION + 2;
@@ -103,7 +104,7 @@ std::unique_ptr<ISimpleExpression> SimpleExpressionMatchers::ProcessConditionalO
     return std::make_unique<SimpleExpressionConditionalOperator>(std::move(condition), std::move(trueExpression), std::move(falseExpression));
 }
 
-std::unique_ptr<ISimpleExpression> SimpleExpressionMatchers::ProcessOperand(SequenceResult<SimpleParserValue>& result) const
+std::unique_ptr<ISimpleExpression> SimpleExpressionMatchers::ProcessOperand(SequenceResult<SimpleParserValue>& result)
 {
     const auto& operandToken = result.NextCapture(CAPTURE_OPERAND);
 
@@ -133,7 +134,7 @@ std::unique_ptr<ISimpleExpression> SimpleExpressionMatchers::ProcessExpression(S
         return nullptr;
 
     std::vector<std::unique_ptr<ISimpleExpression>> operands;
-    std::list<std::pair<unsigned, const SimpleExpressionBinaryOperationType*>> operators;
+    std::list<std::pair<size_t, const SimpleExpressionBinaryOperationType*>> operators;
 
     while (true)
     {
@@ -200,7 +201,7 @@ std::unique_ptr<ISimpleExpression> SimpleExpressionMatchers::ProcessExpression(S
     }
 
     operators.sort(
-        [](const std::pair<unsigned, const SimpleExpressionBinaryOperationType*>& p1, const std::pair<unsigned, const SimpleExpressionBinaryOperationType*>& p2)
+        [](const std::pair<size_t, const SimpleExpressionBinaryOperationType*>& p1, const std::pair<size_t, const SimpleExpressionBinaryOperationType*>& p2)
         {
             if (p1.second->m_precedence != p2.second->m_precedence)
                 return p1.second->m_precedence > p2.second->m_precedence;
@@ -219,7 +220,7 @@ std::unique_ptr<ISimpleExpression> SimpleExpressionMatchers::ProcessExpression(S
 
         operators.pop_back();
 
-        for (auto& [opIndex, _] : operators)
+        for (auto& opIndex : operators | std::views::keys)
         {
             if (opIndex > operatorIndex)
                 opIndex--;
diff --git a/src/Parser/Parsing/Simple/Expression/SimpleExpressionMatchers.h b/src/Parser/Parsing/Simple/Expression/SimpleExpressionMatchers.h
index 021688e2..aaf02bc9 100644
--- a/src/Parser/Parsing/Simple/Expression/SimpleExpressionMatchers.h
+++ b/src/Parser/Parsing/Simple/Expression/SimpleExpressionMatchers.h
@@ -59,7 +59,7 @@ private:
     std::unique_ptr<ISimpleExpression> ProcessExpressionInParenthesis(SequenceResult<SimpleParserValue>& result) const;
     std::unique_ptr<ISimpleExpression> ProcessConditionalOperation(std::unique_ptr<ISimpleExpression> condition,
                                                                    SequenceResult<SimpleParserValue>& result) const;
-    std::unique_ptr<ISimpleExpression> ProcessOperand(SequenceResult<SimpleParserValue>& result) const;
+    static std::unique_ptr<ISimpleExpression> ProcessOperand(SequenceResult<SimpleParserValue>& result);
 
 public:
     std::unique_ptr<matcher_t> Expression(const supplier_t* labelSupplier) const;
diff --git a/src/Parser/Parsing/Simple/SimpleLexer.cpp b/src/Parser/Parsing/Simple/SimpleLexer.cpp
index 63d5a556..d20fee7f 100644
--- a/src/Parser/Parsing/Simple/SimpleLexer.cpp
+++ b/src/Parser/Parsing/Simple/SimpleLexer.cpp
@@ -14,7 +14,12 @@ SimpleLexer::MultiCharacterTokenLookupEntry::MultiCharacterTokenLookupEntry(cons
 
 SimpleLexer::SimpleLexer(IParserLineStream* stream)
     : AbstractLexer(stream),
-      m_config{false, true, false, true, true, {}},
+      m_config{.m_emit_new_line_tokens = false,
+               .m_read_strings = true,
+               .m_string_escape_sequences = false,
+               .m_read_integer_numbers = true,
+               .m_read_floating_point_numbers = true,
+               .m_multi_character_tokens = {}},
       m_check_for_multi_character_tokens(false),
       m_last_line(1)
 {
diff --git a/src/Parser/Parsing/Simple/SimpleLexer.h b/src/Parser/Parsing/Simple/SimpleLexer.h
index c1220d52..bd6e45dc 100644
--- a/src/Parser/Parsing/Simple/SimpleLexer.h
+++ b/src/Parser/Parsing/Simple/SimpleLexer.h
@@ -7,7 +7,7 @@
 #include <limits>
 #include <memory>
 
-class SimpleLexer : public AbstractLexer<SimpleParserValue>
+class SimpleLexer final : public AbstractLexer<SimpleParserValue>
 {
 public:
     class Config
@@ -30,6 +30,9 @@ public:
         std::vector<MultiCharacterToken> m_multi_character_tokens;
     };
 
+    explicit SimpleLexer(IParserLineStream* stream);
+    SimpleLexer(IParserLineStream* stream, Config config);
+
 protected:
     class MultiCharacterTokenLookupEntry
     {
@@ -41,10 +44,6 @@ protected:
         MultiCharacterTokenLookupEntry(int id, std::string value);
     };
 
-    Config m_config;
-    bool m_check_for_multi_character_tokens;
-    int m_last_line;
-
     std::unique_ptr<MultiCharacterTokenLookupEntry> m_multi_character_token_lookup[std::numeric_limits<uint8_t>::max() + 1];
 
     void AddMultiCharacterTokenConfigToLookup(Config::MultiCharacterToken tokenConfig);
@@ -52,7 +51,7 @@ protected:
 
     SimpleParserValue GetNextToken() override;
 
-public:
-    explicit SimpleLexer(IParserLineStream* stream);
-    SimpleLexer(IParserLineStream* stream, Config config);
+    Config m_config;
+    bool m_check_for_multi_character_tokens;
+    size_t m_last_line;
 };
diff --git a/src/Parser/Parsing/TokenPos.cpp b/src/Parser/Parsing/TokenPos.cpp
index fe9d9c5d..d8dcf469 100644
--- a/src/Parser/Parsing/TokenPos.cpp
+++ b/src/Parser/Parsing/TokenPos.cpp
@@ -1,15 +1,18 @@
 #include "TokenPos.h"
 
-const std::string TokenPos::EMPTY_FILENAME;
+namespace
+{
+    const std::string EMPTY_FILENAME;
+}
 
 TokenPos::TokenPos()
     : m_filename(EMPTY_FILENAME),
-      m_line(1),
-      m_column(1)
+      m_line(1uz),
+      m_column(1uz)
 {
 }
 
-TokenPos::TokenPos(const std::string& filename, const int line, const int column)
+TokenPos::TokenPos(const std::string& filename, const size_t line, const size_t column)
     : m_filename(filename),
       m_line(line),
       m_column(column)
diff --git a/src/Parser/Parsing/TokenPos.h b/src/Parser/Parsing/TokenPos.h
index 103b2dd5..7ceadd6d 100644
--- a/src/Parser/Parsing/TokenPos.h
+++ b/src/Parser/Parsing/TokenPos.h
@@ -5,13 +5,11 @@
 
 class TokenPos
 {
-    static const std::string EMPTY_FILENAME;
-
 public:
-    std::reference_wrapper<const std::string> m_filename;
-    int m_line;
-    int m_column;
-
     TokenPos();
-    TokenPos(const std::string& filename, int line, int column);
+    TokenPos(const std::string& filename, size_t line, size_t column);
+
+    std::reference_wrapper<const std::string> m_filename;
+    size_t m_line;
+    size_t m_column;
 };
diff --git a/src/Utils/Utils/Arguments/ArgumentParser.cpp b/src/Utils/Utils/Arguments/ArgumentParser.cpp
index 1f89a5ed..caff4ce1 100644
--- a/src/Utils/Utils/Arguments/ArgumentParser.cpp
+++ b/src/Utils/Utils/Arguments/ArgumentParser.cpp
@@ -42,7 +42,7 @@ bool ArgumentParser::ParseArguments(std::vector<std::string>& args)
     m_path = args[0];
 
     const auto argCount = args.size();
-    for (unsigned argIndex = 1u; argIndex < argCount; argIndex++)
+    for (auto argIndex = 1uz; argIndex < argCount; argIndex++)
     {
         auto& arg = args[argIndex];
 
@@ -85,7 +85,7 @@ bool ArgumentParser::ParseArguments(std::vector<std::string>& args)
                 return false;
             }
 
-            if (m_matched_options.find(matchedOption) != m_matched_options.end())
+            if (m_matched_options.contains(matchedOption))
             {
                 if (!matchedOption->m_multi_use)
                 {
@@ -106,7 +106,7 @@ bool ArgumentParser::ParseArguments(std::vector<std::string>& args)
             }
 
             auto& parameters = m_matched_options[matchedOption];
-            for (unsigned parameterIndex = 0; parameterIndex < parameterCount; parameterIndex++)
+            for (auto parameterIndex = 0uz; parameterIndex < parameterCount; parameterIndex++)
             {
                 std::string& param = args[argIndex + parameterIndex + 1];
 
@@ -116,14 +116,14 @@ bool ArgumentParser::ParseArguments(std::vector<std::string>& args)
                     return false;
                 }
 
-                parameters.push_back(param);
+                parameters.emplace_back(param);
             }
 
             argIndex += parameterCount;
         }
         else
         {
-            m_matched_arguments.push_back(arg);
+            m_matched_arguments.emplace_back(arg);
         }
     }
 
diff --git a/src/ZoneCodeGeneratorLib/Domain/Computations/MemberDeclarationModifierComputations.cpp b/src/ZoneCodeGeneratorLib/Domain/Computations/MemberDeclarationModifierComputations.cpp
index 2b9e99ba..aec0c366 100644
--- a/src/ZoneCodeGeneratorLib/Domain/Computations/MemberDeclarationModifierComputations.cpp
+++ b/src/ZoneCodeGeneratorLib/Domain/Computations/MemberDeclarationModifierComputations.cpp
@@ -12,18 +12,18 @@ DeclarationModifierComputations::DeclarationModifierComputations(const MemberInf
       m_modifier_indices(std::move(modifierIndices))
 {
     auto combinedIndex = 0;
-    auto arraySizes = MemberComputations(m_information).GetArraySizes();
+    const auto arraySizes = MemberComputations(m_information).GetArraySizes();
     std::vector<int> sizePerDepth(arraySizes.size());
 
     auto currentDepthSize = 1;
-    for (int i = arraySizes.size(); i > 0; i--)
+    for (int i = static_cast<int>(arraySizes.size()); i > 0; i--)
     {
         sizePerDepth[i - 1] = currentDepthSize;
         currentDepthSize *= arraySizes[i - 1];
     }
 
     auto currentDepth = 0;
-    for (auto modifierIndex : m_modifier_indices)
+    for (const auto modifierIndex : m_modifier_indices)
     {
         combinedIndex += sizePerDepth[currentDepth++] * modifierIndex;
     }
@@ -62,7 +62,7 @@ std::vector<DeclarationModifier*> DeclarationModifierComputations::GetFollowingD
 
     if (m_modifier_indices.size() + 1 < declarationModifiers.size())
     {
-        for (auto i = declarationModifiers.begin() + m_modifier_indices.size() + 1; i != declarationModifiers.end(); ++i)
+        for (auto i = declarationModifiers.begin() + m_modifier_indices.size() + 1uz; i != declarationModifiers.end(); ++i)
         {
             following.push_back(i->get());
         }
diff --git a/src/ZoneCodeGeneratorLib/Parsing/Commands/Impl/CommandsParserState.cpp b/src/ZoneCodeGeneratorLib/Parsing/Commands/Impl/CommandsParserState.cpp
index 75f6c66b..00ed3005 100644
--- a/src/ZoneCodeGeneratorLib/Parsing/Commands/Impl/CommandsParserState.cpp
+++ b/src/ZoneCodeGeneratorLib/Parsing/Commands/Impl/CommandsParserState.cpp
@@ -1,5 +1,63 @@
 #include "CommandsParserState.h"
 
+namespace
+{
+    MemberInformation* GetMemberWithName(const std::string& memberName, const StructureInformation* type)
+    {
+        for (const auto& member : type->m_ordered_members)
+        {
+            if (member->m_member->m_name == memberName)
+            {
+                return member.get();
+            }
+        }
+
+        return nullptr;
+    }
+
+    bool GetNextTypenameSeparatorPos(const std::string& typeNameValue, const size_t startPos, size_t& separatorPos)
+    {
+        const auto typeNameValueSize = typeNameValue.size();
+        for (auto currentHead = startPos + 1; currentHead < typeNameValueSize; currentHead++)
+        {
+            if (typeNameValue[currentHead] == ':' && typeNameValue[currentHead - 1] == ':')
+            {
+                separatorPos = currentHead - 1;
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    bool ExtractMembersFromTypenameInternal(const std::string& typeNameValue,
+                                            size_t typeNameOffset,
+                                            const StructureInformation* type,
+                                            std::vector<MemberInformation*>& members)
+    {
+        auto startOffset = typeNameOffset;
+        while (GetNextTypenameSeparatorPos(typeNameValue, typeNameOffset, typeNameOffset))
+        {
+            auto* foundMember = GetMemberWithName(std::string(typeNameValue, startOffset, typeNameOffset - startOffset), type);
+
+            if (foundMember == nullptr)
+                return false;
+
+            members.push_back(foundMember);
+            type = foundMember->m_type;
+            typeNameOffset += 2;
+            startOffset = typeNameOffset;
+        }
+
+        auto* foundMember = GetMemberWithName(std::string(typeNameValue, startOffset, typeNameValue.size() - startOffset), type);
+        if (foundMember == nullptr)
+            return false;
+
+        members.push_back(foundMember);
+        return true;
+    }
+} // namespace
+
 CommandsParserState::CommandsParserState(IDataRepository* repository)
     : m_repository(repository),
       m_in_use(nullptr)
@@ -36,63 +94,8 @@ void CommandsParserState::SetInUse(StructureInformation* structure)
     m_in_use = structure;
 }
 
-MemberInformation* CommandsParserState::GetMemberWithName(const std::string& memberName, StructureInformation* type)
-{
-    for (const auto& member : type->m_ordered_members)
-    {
-        if (member->m_member->m_name == memberName)
-        {
-            return member.get();
-        }
-    }
-
-    return nullptr;
-}
-
-bool CommandsParserState::GetNextTypenameSeparatorPos(const std::string& typeNameValue, const unsigned startPos, unsigned& separatorPos)
-{
-    const auto typeNameValueSize = typeNameValue.size();
-    for (auto currentHead = startPos + 1; currentHead < typeNameValueSize; currentHead++)
-    {
-        if (typeNameValue[currentHead] == ':' && typeNameValue[currentHead - 1] == ':')
-        {
-            separatorPos = currentHead - 1;
-            return true;
-        }
-    }
-
-    return false;
-}
-
-bool CommandsParserState::ExtractMembersFromTypenameInternal(const std::string& typeNameValue,
-                                                             unsigned typeNameOffset,
-                                                             StructureInformation* type,
-                                                             std::vector<MemberInformation*>& members)
-{
-    auto startOffset = typeNameOffset;
-    while (GetNextTypenameSeparatorPos(typeNameValue, typeNameOffset, typeNameOffset))
-    {
-        auto* foundMember = GetMemberWithName(std::string(typeNameValue, startOffset, typeNameOffset - startOffset), type);
-
-        if (foundMember == nullptr)
-            return false;
-
-        members.push_back(foundMember);
-        type = foundMember->m_type;
-        typeNameOffset += 2;
-        startOffset = typeNameOffset;
-    }
-
-    auto* foundMember = GetMemberWithName(std::string(typeNameValue, startOffset, typeNameValue.size() - startOffset), type);
-    if (foundMember == nullptr)
-        return false;
-
-    members.push_back(foundMember);
-    return true;
-}
-
 bool CommandsParserState::GetMembersFromTypename(const std::string& typeNameValue,
-                                                 StructureInformation* baseType,
+                                                 const StructureInformation* baseType,
                                                  std::vector<MemberInformation*>& members) const
 {
     return m_in_use != nullptr && ExtractMembersFromTypenameInternal(typeNameValue, 0, m_in_use, members)
@@ -114,7 +117,7 @@ bool CommandsParserState::GetTypenameAndMembersFromTypename(const std::string& t
     }
 
     DataDefinition* foundDefinition = nullptr;
-    unsigned currentSeparatorPos = 0;
+    auto currentSeparatorPos = 0uz;
     while (GetNextTypenameSeparatorPos(typeNameValue, currentSeparatorPos, currentSeparatorPos))
     {
         std::string currentTypename(typeNameValue, 0, currentSeparatorPos);
@@ -134,7 +137,7 @@ bool CommandsParserState::GetTypenameAndMembersFromTypename(const std::string& t
     if (foundDefinition == nullptr)
         return false;
 
-    auto* definitionWithMembers = dynamic_cast<DefinitionWithMembers*>(foundDefinition);
+    const auto* definitionWithMembers = dynamic_cast<DefinitionWithMembers*>(foundDefinition);
     if (definitionWithMembers == nullptr)
         return false;
 
diff --git a/src/ZoneCodeGeneratorLib/Parsing/Commands/Impl/CommandsParserState.h b/src/ZoneCodeGeneratorLib/Parsing/Commands/Impl/CommandsParserState.h
index be50ef18..a38b322f 100644
--- a/src/ZoneCodeGeneratorLib/Parsing/Commands/Impl/CommandsParserState.h
+++ b/src/ZoneCodeGeneratorLib/Parsing/Commands/Impl/CommandsParserState.h
@@ -19,17 +19,10 @@ public:
     [[nodiscard]] StructureInformation* GetInUse() const;
     void SetInUse(StructureInformation* structure);
 
-    bool GetMembersFromTypename(const std::string& typeNameValue, StructureInformation* baseType, std::vector<MemberInformation*>& members) const;
+    bool GetMembersFromTypename(const std::string& typeNameValue, const StructureInformation* baseType, std::vector<MemberInformation*>& members) const;
     bool GetTypenameAndMembersFromTypename(const std::string& typeNameValue, StructureInformation*& structure, std::vector<MemberInformation*>& members) const;
 
 private:
-    static MemberInformation* GetMemberWithName(const std::string& memberName, StructureInformation* type);
-    static bool GetNextTypenameSeparatorPos(const std::string& typeNameValue, unsigned startPos, unsigned& separatorPos);
-    static bool ExtractMembersFromTypenameInternal(const std::string& typeNameValue,
-                                                   unsigned typeNameOffset,
-                                                   StructureInformation* type,
-                                                   std::vector<MemberInformation*>& members);
-
     IDataRepository* m_repository;
     StructureInformation* m_in_use;
 };
diff --git a/src/ZoneCodeGeneratorLib/Parsing/Commands/Matcher/CommandsCommonMatchers.cpp b/src/ZoneCodeGeneratorLib/Parsing/Commands/Matcher/CommandsCommonMatchers.cpp
index 3bc815df..8bed3923 100644
--- a/src/ZoneCodeGeneratorLib/Parsing/Commands/Matcher/CommandsCommonMatchers.cpp
+++ b/src/ZoneCodeGeneratorLib/Parsing/Commands/Matcher/CommandsCommonMatchers.cpp
@@ -6,6 +6,7 @@
 #include "Domain/Evaluation/Operation.h"
 
 #include <list>
+#include <ranges>
 #include <sstream>
 #include <type_traits>
 #include <vector>
@@ -353,7 +354,7 @@ std::unique_ptr<IEvaluation>
         currentType = nullptr;
 
     std::vector<std::unique_ptr<IEvaluation>> operands;
-    std::list<std::pair<unsigned, const OperationType*>> operators;
+    std::list<std::pair<size_t, const OperationType*>> operators;
 
     while (true)
     {
@@ -384,7 +385,7 @@ std::unique_ptr<IEvaluation>
     }
 
     operators.sort(
-        [](const std::pair<unsigned, const OperationType*>& p1, const std::pair<unsigned, const OperationType*>& p2)
+        [](const std::pair<size_t, const OperationType*>& p1, const std::pair<size_t, const OperationType*>& p2)
         {
             if (p1.second->m_precedence != p2.second->m_precedence)
                 return p1.second->m_precedence > p2.second->m_precedence;
@@ -402,7 +403,7 @@ std::unique_ptr<IEvaluation>
 
         operators.pop_back();
 
-        for (auto& [opIndex, _] : operators)
+        for (auto& opIndex : operators | std::views::keys)
         {
             if (opIndex > operatorIndex)
                 opIndex--;
diff --git a/test/ParserTestUtils/Parsing/Mock/MockLexer.h b/test/ParserTestUtils/Parsing/Mock/MockLexer.h
index ae484456..f48c303a 100644
--- a/test/ParserTestUtils/Parsing/Mock/MockLexer.h
+++ b/test/ParserTestUtils/Parsing/Mock/MockLexer.h
@@ -3,18 +3,12 @@
 #include "Parsing/ILexer.h"
 #include "Utils/ClassUtils.h"
 
+#include <concepts>
 #include <iterator>
 #include <vector>
 
-template<typename TokenType> class MockLexer final : public ILexer<TokenType>
+template<std::derived_from<IParserValue> TokenType> class MockLexer final : public ILexer<TokenType>
 {
-    // TokenType must inherit IParserValue
-    static_assert(std::is_base_of<IParserValue, TokenType>::value);
-
-    std::vector<TokenType> m_tokens;
-    TokenType m_eof;
-    size_t m_pop_count;
-
 public:
     MockLexer(std::initializer_list<Movable<TokenType>> tokens, TokenType eof)
         : m_tokens(std::make_move_iterator(tokens.begin()), std::make_move_iterator(tokens.end())),
@@ -36,7 +30,7 @@ public:
     MockLexer& operator=(const MockLexer& other) = delete;
     MockLexer& operator=(MockLexer&& other) noexcept = default;
 
-    const TokenType& GetToken(const unsigned index) override
+    const TokenType& GetToken(const size_t index) override
     {
         const auto absoluteIndex = m_pop_count + index;
         if (absoluteIndex < m_tokens.size())
@@ -45,10 +39,10 @@ public:
         return m_eof;
     }
 
-    void PopTokens(const int amount) override
+    void PopTokens(const size_t amount) override
     {
         assert(amount >= 0);
-        m_pop_count += static_cast<size_t>(amount);
+        m_pop_count += amount;
     }
 
     bool IsEof() override
@@ -70,4 +64,9 @@ public:
     {
         return ParserLine();
     }
+
+private:
+    std::vector<TokenType> m_tokens;
+    TokenType m_eof;
+    size_t m_pop_count;
 };