v3.5.1v3.5.1

7 files changed, 383 insertions, 284 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 20e4036e..b4dd2b52 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,7 +33,7 @@ if (CMAKE_BINARY_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
 endif()
 
 project(Catch2
-  VERSION 3.5.0 # CML version placeholder, don't delete
+  VERSION 3.5.1 # CML version placeholder, don't delete
   LANGUAGES CXX
   # HOMEPAGE_URL is not supported until CMake version 3.12, which
   # we do not target yet.
diff --git a/docs/release-notes.md b/docs/release-notes.md
index 9751f2ce..0449ed0e 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -2,6 +2,7 @@
 
 # Release notes
 **Contents**<br>
+[3.5.1](#351)<br>
 [3.5.0](#350)<br>
 [3.4.0](#340)<br>
 [3.3.2](#332)<br>
@@ -58,6 +59,17 @@
 [Even Older versions](#even-older-versions)<br>
 
 
+## 3.5.1
+
+### Improvements
+* Significantly improved performance of the CLI parsing.
+  * This includes the cost of preparing the CLI parser, so Catch2's binaries start much faster.
+
+### Miscellaneous
+* Added support for Bazel modules (#2781)
+* Added CMake option to disable the build reproducibility settings (#2785)
+* Added `log` library linking to the Meson build (#2784)
+
 
 ## 3.5.0
 
diff --git a/extras/catch_amalgamated.cpp b/extras/catch_amalgamated.cpp
index cfc38a46..30e2d9f2 100644
--- a/extras/catch_amalgamated.cpp
+++ b/extras/catch_amalgamated.cpp
@@ -6,8 +6,8 @@
 
 // SPDX-License-Identifier: BSL-1.0
 
-//  Catch v3.5.0
-//  Generated: 2023-12-11 00:51:07.662625
+//  Catch v3.5.1
+//  Generated: 2023-12-31 15:10:55.864983
 //  ----------------------------------------------------------
 //  This file is an amalgamation of multiple different files.
 //  You probably shouldn't edit it directly.
@@ -2273,7 +2273,7 @@ namespace Catch {
     }
 
     Version const& libraryVersion() {
-        static Version version( 3, 5, 0, "", 0 );
+        static Version version( 3, 5, 1, "", 0 );
         return version;
     }
 
@@ -2415,9 +2415,7 @@ namespace Catch {
 
 
 
-#include <algorithm>
 #include <cassert>
-#include <iomanip>
 
 namespace Catch {
 
@@ -2627,13 +2625,29 @@ namespace {
             ;
     }
 
-    std::string normaliseOpt( std::string const& optName ) {
-#ifdef CATCH_PLATFORM_WINDOWS
-        if ( optName[0] == '/' )
-            return "-" + optName.substr( 1 );
-        else
+    Catch::StringRef normaliseOpt( Catch::StringRef optName ) {
+        if ( optName[0] == '-'
+#if defined(CATCH_PLATFORM_WINDOWS)
+             || optName[0] == '/'
 #endif
-            return optName;
+        ) {
+            return optName.substr( 1, optName.size() );
+        }
+
+        return optName;
+    }
+
+    static size_t find_first_separator(Catch::StringRef sr) {
+        auto is_separator = []( char c ) {
+            return c == ' ' || c == ':' || c == '=';
+        };
+        size_t pos = 0;
+        while (pos < sr.size()) {
+            if (is_separator(sr[pos])) { return pos; }
+            ++pos;
+        }
+
+        return Catch::StringRef::npos;
     }
 
 } // namespace
@@ -2651,23 +2665,23 @@ namespace Catch {
                 }
 
                 if ( it != itEnd ) {
-                    auto const& next = *it;
+                    StringRef next = *it;
                     if ( isOptPrefix( next[0] ) ) {
-                        auto delimiterPos = next.find_first_of( " :=" );
-                        if ( delimiterPos != std::string::npos ) {
+                        auto delimiterPos = find_first_separator(next);
+                        if ( delimiterPos != StringRef::npos ) {
                             m_tokenBuffer.push_back(
                                 { TokenType::Option,
                                   next.substr( 0, delimiterPos ) } );
                             m_tokenBuffer.push_back(
                                 { TokenType::Argument,
-                                  next.substr( delimiterPos + 1 ) } );
+                                  next.substr( delimiterPos + 1, next.size() ) } );
                         } else {
                             if ( next[1] != '-' && next.size() > 2 ) {
-                                std::string opt = "- ";
+                                // Combined short args, e.g. "-ab" for "-a -b"
                                 for ( size_t i = 1; i < next.size(); ++i ) {
-                                    opt[1] = next[i];
                                     m_tokenBuffer.push_back(
-                                        { TokenType::Option, opt } );
+                                        { TokenType::Option,
+                                          next.substr( i, 1 ) } );
                                 }
                             } else {
                                 m_tokenBuffer.push_back(
@@ -2727,12 +2741,12 @@ namespace Catch {
             size_t ParserBase::cardinality() const { return 1; }
 
             InternalParseResult ParserBase::parse( Args const& args ) const {
-                return parse( args.exeName(), TokenStream( args ) );
+                return parse( static_cast<std::string>(args.exeName()), TokenStream( args ) );
             }
 
             ParseState::ParseState( ParseResultType type,
-                                    TokenStream const& remainingTokens ):
-                m_type( type ), m_remainingTokens( remainingTokens ) {}
+                                    TokenStream remainingTokens ):
+                m_type( type ), m_remainingTokens( CATCH_MOVE(remainingTokens) ) {}
 
             ParserResult BoundFlagRef::setFlag( bool flag ) {
                 m_ref = flag;
@@ -2750,34 +2764,34 @@ namespace Catch {
 } // namespace Detail
 
         Detail::InternalParseResult Arg::parse(std::string const&,
-                                               Detail::TokenStream const& tokens) const {
+                                               Detail::TokenStream tokens) const {
             auto validationResult = validate();
             if (!validationResult)
                 return Detail::InternalParseResult(validationResult);
 
-            auto remainingTokens = tokens;
-            auto const& token = *remainingTokens;
+            auto token = *tokens;
             if (token.type != Detail::TokenType::Argument)
                 return Detail::InternalParseResult::ok(Detail::ParseState(
-                    ParseResultType::NoMatch, remainingTokens));
+                    ParseResultType::NoMatch, CATCH_MOVE(tokens)));
 
             assert(!m_ref->isFlag());
             auto valueRef =
                 static_cast<Detail::BoundValueRefBase*>(m_ref.get());
 
-            auto result = valueRef->setValue(remainingTokens->token);
-            if (!result)
-                return Detail::InternalParseResult(result);
+            auto result = valueRef->setValue(static_cast<std::string>(token.token));
+            if ( !result )
+                return Detail::InternalParseResult( result );
             else
-                return Detail::InternalParseResult::ok(Detail::ParseState(
-                    ParseResultType::Matched, ++remainingTokens));
+                return Detail::InternalParseResult::ok(
+                    Detail::ParseState( ParseResultType::Matched,
+                                        CATCH_MOVE( ++tokens ) ) );
         }
 
         Opt::Opt(bool& ref) :
             ParserRefImpl(std::make_shared<Detail::BoundFlagRef>(ref)) {}
 
-        std::vector<Detail::HelpColumns> Opt::getHelpColumns() const {
-            std::ostringstream oss;
+        Detail::HelpColumns Opt::getHelpColumns() const {
+            ReusableStringStream oss;
             bool first = true;
             for (auto const& opt : m_optNames) {
                 if (first)
@@ -2788,10 +2802,10 @@ namespace Catch {
             }
             if (!m_hint.empty())
                 oss << " <" << m_hint << '>';
-            return { { oss.str(), m_description } };
+            return { oss.str(), m_description };
         }
 
-        bool Opt::isMatch(std::string const& optToken) const {
+        bool Opt::isMatch(StringRef optToken) const {
             auto normalisedToken = normaliseOpt(optToken);
             for (auto const& name : m_optNames) {
                 if (normaliseOpt(name) == normalisedToken)
@@ -2801,15 +2815,14 @@ namespace Catch {
         }
 
         Detail::InternalParseResult Opt::parse(std::string const&,
-                                       Detail::TokenStream const& tokens) const {
+                                       Detail::TokenStream tokens) const {
             auto validationResult = validate();
             if (!validationResult)
                 return Detail::InternalParseResult(validationResult);
 
-            auto remainingTokens = tokens;
-            if (remainingTokens &&
-                remainingTokens->type == Detail::TokenType::Option) {
-                auto const& token = *remainingTokens;
+            if (tokens &&
+                tokens->type == Detail::TokenType::Option) {
+                auto const& token = *tokens;
                 if (isMatch(token.token)) {
                     if (m_ref->isFlag()) {
                         auto flagRef =
@@ -2821,35 +2834,35 @@ namespace Catch {
                         if (result.value() ==
                             ParseResultType::ShortCircuitAll)
                             return Detail::InternalParseResult::ok(Detail::ParseState(
-                                result.value(), remainingTokens));
+                                result.value(), CATCH_MOVE(tokens)));
                     } else {
                         auto valueRef =
                             static_cast<Detail::BoundValueRefBase*>(
                                 m_ref.get());
-                        ++remainingTokens;
-                        if (!remainingTokens)
+                        ++tokens;
+                        if (!tokens)
                             return Detail::InternalParseResult::runtimeError(
                                 "Expected argument following " +
                                 token.token);
-                        auto const& argToken = *remainingTokens;
+                        auto const& argToken = *tokens;
                         if (argToken.type != Detail::TokenType::Argument)
                             return Detail::InternalParseResult::runtimeError(
                                 "Expected argument following " +
                                 token.token);
-                        const auto result = valueRef->setValue(argToken.token);
+                        const auto result = valueRef->setValue(static_cast<std::string>(argToken.token));
                         if (!result)
                             return Detail::InternalParseResult(result);
                         if (result.value() ==
                             ParseResultType::ShortCircuitAll)
                             return Detail::InternalParseResult::ok(Detail::ParseState(
-                                result.value(), remainingTokens));
+                                result.value(), CATCH_MOVE(tokens)));
                     }
                     return Detail::InternalParseResult::ok(Detail::ParseState(
-                        ParseResultType::Matched, ++remainingTokens));
+                        ParseResultType::Matched, CATCH_MOVE(++tokens)));
                 }
             }
             return Detail::InternalParseResult::ok(
-                Detail::ParseState(ParseResultType::NoMatch, remainingTokens));
+                Detail::ParseState(ParseResultType::NoMatch, CATCH_MOVE(tokens)));
         }
 
         Detail::Result Opt::validate() const {
@@ -2881,9 +2894,9 @@ namespace Catch {
 
         Detail::InternalParseResult
             ExeName::parse(std::string const&,
-                           Detail::TokenStream const& tokens) const {
+                           Detail::TokenStream tokens) const {
             return Detail::InternalParseResult::ok(
-                Detail::ParseState(ParseResultType::NoMatch, tokens));
+                Detail::ParseState(ParseResultType::NoMatch, CATCH_MOVE(tokens)));
         }
 
         ParserResult ExeName::set(std::string const& newName) {
@@ -2913,9 +2926,9 @@ namespace Catch {
 
         std::vector<Detail::HelpColumns> Parser::getHelpColumns() const {
             std::vector<Detail::HelpColumns> cols;
+            cols.reserve( m_options.size() );
             for ( auto const& o : m_options ) {
-                auto childCols = o.getHelpColumns();
-                cols.insert( cols.end(), childCols.begin(), childCols.end() );
+                cols.push_back(o.getHelpColumns());
             }
             return cols;
         }
@@ -2953,12 +2966,12 @@ namespace Catch {
 
             optWidth = ( std::min )( optWidth, consoleWidth / 2 );
 
-            for ( auto const& cols : rows ) {
-                auto row = TextFlow::Column( cols.left )
+            for ( auto& cols : rows ) {
+                auto row = TextFlow::Column( CATCH_MOVE(cols.left) )
                                .width( optWidth )
                                .indent( 2 ) +
                            TextFlow::Spacer( 4 ) +
-                           TextFlow::Column( cols.right )
+                           TextFlow::Column( static_cast<std::string>(cols.descriptions) )
                                .width( consoleWidth - 7 - optWidth );
                 os << row << '\n';
             }
@@ -2980,7 +2993,7 @@ namespace Catch {
 
         Detail::InternalParseResult
         Parser::parse( std::string const& exeName,
-                       Detail::TokenStream const& tokens ) const {
+                       Detail::TokenStream tokens ) const {
 
             struct ParserInfo {
                 ParserBase const* parser = nullptr;
@@ -2998,7 +3011,7 @@ namespace Catch {
             m_exeName.set( exeName );
 
             auto result = Detail::InternalParseResult::ok(
-                Detail::ParseState( ParseResultType::NoMatch, tokens ) );
+                Detail::ParseState( ParseResultType::NoMatch, CATCH_MOVE(tokens) ) );
             while ( result.value().remainingTokens() ) {
                 bool tokenParsed = false;
 
@@ -3006,7 +3019,7 @@ namespace Catch {
                     if ( parseInfo.parser->cardinality() == 0 ||
                          parseInfo.count < parseInfo.parser->cardinality() ) {
                         result = parseInfo.parser->parse(
-                            exeName, result.value().remainingTokens() );
+                            exeName, CATCH_MOVE(result).value().remainingTokens() );
                         if ( !result )
                             return result;
                         if ( result.value().type() !=
@@ -3032,7 +3045,7 @@ namespace Catch {
         Args::Args(int argc, char const* const* argv) :
             m_exeName(argv[0]), m_args(argv + 1, argv + argc) {}
 
-        Args::Args(std::initializer_list<std::string> args) :
+        Args::Args(std::initializer_list<StringRef> args) :
             m_exeName(*args.begin()),
             m_args(args.begin() + 1, args.end()) {}
 
@@ -3338,8 +3351,8 @@ namespace Catch {
                 ( "split the tests to execute into this many groups" )
             | Opt( setShardIndex, "shard index" )
                 ["--shard-index"]
-                ( "index of the group of tests to execute (see --shard-count)" ) |
-            Opt( config.allowZeroTests )
+                ( "index of the group of tests to execute (see --shard-count)" )
+            | Opt( config.allowZeroTests )
                 ["--allow-running-no-tests"]
                 ( "Treat 'No tests run' as a success" )
             | Arg( config.testsOrTags, "test name|pattern|tags" )
@@ -4641,7 +4654,6 @@ Catch::LeakDetector::~LeakDetector() {
 
 
 
-
 namespace Catch {
     namespace {
 
@@ -6527,7 +6539,6 @@ namespace Catch {
             return sorted;
         }
         case TestRunOrder::Randomized: {
-            seedRng(config);
             using TestWithHash = std::pair<TestCaseInfoHasher::hash_t, TestCaseHandle>;
 
             TestCaseInfoHasher h{ config.rngSeed() };
@@ -7390,23 +7401,36 @@ namespace Catch {
             return os;
         }
 
-        Columns Column::operator+( Column const& other ) {
+        Columns operator+(Column const& lhs, Column const& rhs) {
             Columns cols;
-            cols += *this;
-            cols += other;
+            cols += lhs;
+            cols += rhs;
             return cols;
         }
-
-        Columns& Columns::operator+=( Column const& col ) {
-            m_columns.push_back( col );
-            return *this;
+        Columns operator+(Column&& lhs, Column&& rhs) {
+            Columns cols;
+            cols += CATCH_MOVE( lhs );
+            cols += CATCH_MOVE( rhs );
+            return cols;
         }
 
-        Columns Columns::operator+( Column const& col ) {
-            Columns combined = *this;
-            combined += col;
+        Columns& operator+=(Columns& lhs, Column const& rhs) {
+            lhs.m_columns.push_back( rhs );
+            return lhs;
+        }
+        Columns& operator+=(Columns& lhs, Column&& rhs) {
+            lhs.m_columns.push_back( CATCH_MOVE(rhs) );
+            return lhs;
+        }
+        Columns operator+( Columns const& lhs, Column const& rhs ) {
+            auto combined( lhs );
+            combined += rhs;
             return combined;
         }
+        Columns operator+( Columns&& lhs, Column&& rhs ) {
+            lhs += CATCH_MOVE( rhs );
+            return CATCH_MOVE( lhs );
+        }
 
     } // namespace TextFlow
 } // namespace Catch
@@ -8881,11 +8905,10 @@ public:
             *this << RowBreak();
 
 			TextFlow::Columns headerCols;
-			auto spacer = TextFlow::Spacer(2);
 			for (auto const& info : m_columnInfos) {
                 assert(info.width > 2);
 				headerCols += TextFlow::Column(info.name).width(info.width - 2);
-				headerCols += spacer;
+                headerCols += TextFlow::Spacer( 2 );
 			}
 			m_os << headerCols << '\n';
 
diff --git a/extras/catch_amalgamated.hpp b/extras/catch_amalgamated.hpp
index bec588d4..4f075857 100644
--- a/extras/catch_amalgamated.hpp
+++ b/extras/catch_amalgamated.hpp
@@ -6,8 +6,8 @@
 
 // SPDX-License-Identifier: BSL-1.0
 
-//  Catch v3.5.0
-//  Generated: 2023-12-11 00:51:06.770598
+//  Catch v3.5.1
+//  Generated: 2023-12-31 15:10:53.044176
 //  ----------------------------------------------------------
 //  This file is an amalgamation of multiple different files.
 //  You probably shouldn't edit it directly.
@@ -690,6 +690,8 @@ namespace Catch {
         using size_type = std::size_t;
         using const_iterator = const char*;
 
+        static constexpr size_type npos{ static_cast<size_type>( -1 ) };
+
     private:
         static constexpr char const* const s_empty = "";
 
@@ -740,7 +742,7 @@ namespace Catch {
         }
 
         // Returns a substring of [start, start + length).
-        // If start + length > size(), then the substring is [start, start + size()).
+        // If start + length > size(), then the substring is [start, size()).
         // If start > size(), then the substring is empty.
         constexpr StringRef substr(size_type start, size_type length) const noexcept {
             if (start < m_size) {
@@ -1969,12 +1971,12 @@ namespace Catch {
 
             template <typename Clock>
             int warmup() {
-                return run_for_at_least<Clock>(std::chrono::duration_cast<IDuration>(warmup_time), warmup_seed, &resolution<Clock>)
+                return run_for_at_least<Clock>(warmup_time, warmup_seed, &resolution<Clock>)
                     .iterations;
             }
             template <typename Clock>
             EnvironmentEstimate estimate_clock_resolution(int iterations) {
-                auto r = run_for_at_least<Clock>(std::chrono::duration_cast<IDuration>(clock_resolution_estimation_time), iterations, &resolution<Clock>)
+                auto r = run_for_at_least<Clock>(clock_resolution_estimation_time, iterations, &resolution<Clock>)
                     .result;
                 return {
                     FDuration(mean(r.data(), r.data() + r.size())),
@@ -1996,7 +1998,7 @@ namespace Catch {
                 };
                 time_clock(1);
                 int iters = clock_cost_estimation_iterations;
-                auto&& r = run_for_at_least<Clock>(std::chrono::duration_cast<IDuration>(clock_cost_estimation_time), iters, time_clock);
+                auto&& r = run_for_at_least<Clock>(clock_cost_estimation_time, iters, time_clock);
                 std::vector<double> times;
                 int nsamples = static_cast<int>(std::ceil(time_limit / r.elapsed));
                 times.reserve(static_cast<size_t>(nsamples));
@@ -3639,141 +3641,6 @@ namespace Catch {
 #define CATCH_REPORTER_SPEC_PARSER_HPP_INCLUDED
 
 
-
-#ifndef CATCH_CONSOLE_COLOUR_HPP_INCLUDED
-#define CATCH_CONSOLE_COLOUR_HPP_INCLUDED
-
-
-#include <iosfwd>
-#include <cstdint>
-
-namespace Catch {
-
-    enum class ColourMode : std::uint8_t;
-    class IStream;
-
-    struct Colour {
-        enum Code {
-            None = 0,
-
-            White,
-            Red,
-            Green,
-            Blue,
-            Cyan,
-            Yellow,
-            Grey,
-
-            Bright = 0x10,
-
-            BrightRed = Bright | Red,
-            BrightGreen = Bright | Green,
-            LightGrey = Bright | Grey,
-            BrightWhite = Bright | White,
-            BrightYellow = Bright | Yellow,
-
-            // By intention
-            FileName = LightGrey,
-            Warning = BrightYellow,
-            ResultError = BrightRed,
-            ResultSuccess = BrightGreen,
-            ResultExpectedFailure = Warning,
-
-            Error = BrightRed,
-            Success = Green,
-            Skip = LightGrey,
-
-            OriginalExpression = Cyan,
-            ReconstructedExpression = BrightYellow,
-
-            SecondaryText = LightGrey,
-            Headers = White
-        };
-    };
-
-    class ColourImpl {
-    protected:
-        //! The associated stream of this ColourImpl instance
-        IStream* m_stream;
-    public:
-        ColourImpl( IStream* stream ): m_stream( stream ) {}
-
-        //! RAII wrapper around writing specific colour of text using specific
-        //! colour impl into a stream.
-        class ColourGuard {
-            ColourImpl const* m_colourImpl;
-            Colour::Code m_code;
-            bool m_engaged = false;
-
-        public:
-            //! Does **not** engage the guard/start the colour
-            ColourGuard( Colour::Code code,
-                         ColourImpl const* colour );
-
-            ColourGuard( ColourGuard const& rhs ) = delete;
-            ColourGuard& operator=( ColourGuard const& rhs ) = delete;
-
-            ColourGuard( ColourGuard&& rhs ) noexcept;
-            ColourGuard& operator=( ColourGuard&& rhs ) noexcept;
-
-            //! Removes colour _if_ the guard was engaged
-            ~ColourGuard();
-
-            /**
-             * Explicitly engages colour for given stream.
-             *
-             * The API based on operator<< should be preferred.
-             */
-            ColourGuard& engage( std::ostream& stream ) &;
-            /**
-             * Explicitly engages colour for given stream.
-             *
-             * The API based on operator<< should be preferred.
-             */
-            ColourGuard&& engage( std::ostream& stream ) &&;
-
-        private:
-            //! Engages the guard and starts using colour
-            friend std::ostream& operator<<( std::ostream& lhs,
-                                             ColourGuard& guard ) {
-                guard.engageImpl( lhs );
-                return lhs;
-            }
-            //! Engages the guard and starts using colour
-            friend std::ostream& operator<<( std::ostream& lhs,
-                                            ColourGuard&& guard) {
-                guard.engageImpl( lhs );
-                return lhs;
-            }
-
-            void engageImpl( std::ostream& stream );
-
-        };
-
-        virtual ~ColourImpl(); // = default
-        /**
-         * Creates a guard object for given colour and this colour impl
-         *
-         * **Important:**
-         * the guard starts disengaged, and has to be engaged explicitly.
-         */
-        ColourGuard guardColour( Colour::Code colourCode );
-
-    private:
-        virtual void use( Colour::Code colourCode ) const = 0;
-    };
-
-    //! Provides ColourImpl based on global config and target compilation platform
-    Detail::unique_ptr<ColourImpl> makeColourImpl( ColourMode colourSelection,
-                                                   IStream* stream );
-
-    //! Checks if specific colour impl has been compiled into the binary
-    bool isColourImplAvailable( ColourMode colourSelection );
-
-} // end namespace Catch
-
-#endif // CATCH_CONSOLE_COLOUR_HPP_INCLUDED
-
 #include <map>
 #include <string>
 #include <vector>
@@ -4387,17 +4254,16 @@ namespace Catch {
             enum class TokenType { Option, Argument };
             struct Token {
                 TokenType type;
-                std::string token;
+                StringRef token;
             };
 
             // Abstracts iterators into args as a stream of tokens, with option
             // arguments uniformly handled
             class TokenStream {
-                using Iterator = std::vector<std::string>::const_iterator;
+                using Iterator = std::vector<StringRef>::const_iterator;
                 Iterator it;
                 Iterator itEnd;
                 std::vector<Token> m_tokenBuffer;
-
                 void loadBuffer();
 
             public:
@@ -4449,12 +4315,17 @@ namespace Catch {
                 ResultType m_type;
             };
 
-            template <typename T> class ResultValueBase : public ResultBase {
+            template <typename T>
+            class ResultValueBase : public ResultBase {
             public:
-                auto value() const -> T const& {
+                T const& value() const& {
                     enforceOk();
                     return m_value;
                 }
+                T&& value() && {
+                    enforceOk();
+                    return CATCH_MOVE( m_value );
+                }
 
             protected:
                 ResultValueBase( ResultType type ): ResultBase( type ) {}
@@ -4464,13 +4335,23 @@ namespace Catch {
                     if ( m_type == ResultType::Ok )
                         new ( &m_value ) T( other.m_value );
                 }
+                ResultValueBase( ResultValueBase&& other ):
+                    ResultBase( other ) {
+                    if ( m_type == ResultType::Ok )
+                        new ( &m_value ) T( CATCH_MOVE(other.m_value) );
+                }
+
 
-                ResultValueBase( ResultType, T const& value ): ResultBase( ResultType::Ok ) {
+                ResultValueBase( ResultType, T const& value ):
+                    ResultBase( ResultType::Ok ) {
                     new ( &m_value ) T( value );
                 }
+                ResultValueBase( ResultType, T&& value ):
+                    ResultBase( ResultType::Ok ) {
+                    new ( &m_value ) T( CATCH_MOVE(value) );
+                }
 
-                auto operator=( ResultValueBase const& other )
-                    -> ResultValueBase& {
+                ResultValueBase& operator=( ResultValueBase const& other ) {
                     if ( m_type == ResultType::Ok )
                         m_value.~T();
                     ResultBase::operator=( other );
@@ -4478,6 +4359,14 @@ namespace Catch {
                         new ( &m_value ) T( other.m_value );
                     return *this;
                 }
+                ResultValueBase& operator=( ResultValueBase&& other ) {
+                    if ( m_type == ResultType::Ok ) m_value.~T();
+                    ResultBase::operator=( other );
+                    if ( m_type == ResultType::Ok )
+                        new ( &m_value ) T( CATCH_MOVE(other.m_value) );
+                    return *this;
+                }
+
 
                 ~ResultValueBase() override {
                     if ( m_type == ResultType::Ok )
@@ -4505,8 +4394,8 @@ namespace Catch {
                 }
 
                 template <typename U>
-                static auto ok( U const& value ) -> BasicResult {
-                    return { ResultType::Ok, value };
+                static auto ok( U&& value ) -> BasicResult {
+                    return { ResultType::Ok, CATCH_FORWARD(value) };
                 }
                 static auto ok() -> BasicResult { return { ResultType::Ok }; }
                 static auto logicError( std::string&& message )
@@ -4553,12 +4442,15 @@ namespace Catch {
             class ParseState {
             public:
                 ParseState( ParseResultType type,
-                            TokenStream const& remainingTokens );
+                            TokenStream remainingTokens );
 
                 ParseResultType type() const { return m_type; }
-                TokenStream const& remainingTokens() const {
+                TokenStream const& remainingTokens() const& {
                     return m_remainingTokens;
                 }
+                TokenStream&& remainingTokens() && {
+                    return CATCH_MOVE( m_remainingTokens );
+                }
 
             private:
                 ParseResultType m_type;
@@ -4571,7 +4463,7 @@ namespace Catch {
 
             struct HelpColumns {
                 std::string left;
-                std::string right;
+                StringRef descriptions;
             };
 
             template <typename T>
@@ -4731,7 +4623,7 @@ namespace Catch {
                 virtual ~ParserBase() = default;
                 virtual auto validate() const -> Result { return Result::ok(); }
                 virtual auto parse( std::string const& exeName,
-                                    TokenStream const& tokens ) const
+                                    TokenStream tokens ) const
                     -> InternalParseResult = 0;
                 virtual size_t cardinality() const;
 
@@ -4751,8 +4643,8 @@ namespace Catch {
             protected:
                 Optionality m_optionality = Optionality::Optional;
                 std::shared_ptr<BoundRef> m_ref;
-                std::string m_hint;
-                std::string m_description;
+                StringRef m_hint;
+                StringRef m_description;
 
                 explicit ParserRefImpl( std::shared_ptr<BoundRef> const& ref ):
                     m_ref( ref ) {}
@@ -4761,28 +4653,32 @@ namespace Catch {
                 template <typename LambdaT>
                 ParserRefImpl( accept_many_t,
                                LambdaT const& ref,
-                               std::string const& hint ):
+                               StringRef hint ):
                     m_ref( std::make_shared<BoundManyLambda<LambdaT>>( ref ) ),
                     m_hint( hint ) {}
 
                 template <typename T,
                           typename = typename std::enable_if_t<
                               !Detail::is_unary_function<T>::value>>
-                ParserRefImpl( T& ref, std::string const& hint ):
+                ParserRefImpl( T& ref, StringRef hint ):
                     m_ref( std::make_shared<BoundValueRef<T>>( ref ) ),
                     m_hint( hint ) {}
 
                 template <typename LambdaT,
                           typename = typename std::enable_if_t<
                               Detail::is_unary_function<LambdaT>::value>>
-                ParserRefImpl( LambdaT const& ref, std::string const& hint ):
+                ParserRefImpl( LambdaT const& ref, StringRef hint ):
                     m_ref( std::make_shared<BoundLambda<LambdaT>>( ref ) ),
                     m_hint( hint ) {}
 
-                auto operator()( std::string const& description ) -> DerivedT& {
+                DerivedT& operator()( StringRef description ) & {
                     m_description = description;
                     return static_cast<DerivedT&>( *this );
                 }
+                DerivedT&& operator()( StringRef description ) && {
+                    m_description = description;
+                    return static_cast<DerivedT&&>( *this );
+                }
 
                 auto optional() -> DerivedT& {
                     m_optionality = Optionality::Optional;
@@ -4805,7 +4701,7 @@ namespace Catch {
                         return 1;
                 }
 
-                std::string const& hint() const { return m_hint; }
+                StringRef hint() const { return m_hint; }
             };
 
         } // namespace detail
@@ -4819,13 +4715,13 @@ namespace