Remove recursion when stringifying std::tuple

The matcher combinators do not take ownership of the matchers
being combined, which can catch the users off-guard, when code like
this

```cpp
using Catch::Matchers::EndsWith;
using Catch::Matchers::ContainsSubstring;

auto combinedMatcher = EndsWith("as a service")
                       && ContainsSubstring("web scale");

REQUIRE_THAT( getSomeString(), combinedMatcher );
```

leads to use-after-free, as the `combinedMatcher` refers to matcher
temporaries that no longer exists. With this commit, users of Clang,
MSVC or other compiler that understands the `lifetimebound` attribute,
should get a warning.

src/CMakeLists.txt

@@ -98,6 +98,7 @@ set(IMPL_HEADERS
   ${SOURCES_DIR}/internal/catch_jsonwriter.hpp
   ${SOURCES_DIR}/internal/catch_lazy_expr.hpp
   ${SOURCES_DIR}/internal/catch_leak_detector.hpp
+  ${SOURCES_DIR}/internal/catch_lifetimebound.hpp
   ${SOURCES_DIR}/internal/catch_list.hpp
   ${SOURCES_DIR}/internal/catch_logical_traits.hpp
   ${SOURCES_DIR}/internal/catch_message_info.hpp

src/catch2/catch_all.hpp

@@ -79,6 +79,7 @@
 #include <catch2/internal/catch_jsonwriter.hpp>
 #include <catch2/internal/catch_lazy_expr.hpp>
 #include <catch2/internal/catch_leak_detector.hpp>
+#include <catch2/internal/catch_lifetimebound.hpp>
 #include <catch2/internal/catch_list.hpp>
 #include <catch2/internal/catch_logical_traits.hpp>
 #include <catch2/internal/catch_message_info.hpp>

src/catch2/catch_tostring.cpp

@@ -57,6 +57,36 @@ namespace Detail {
         }
     } // end unnamed namespace
 
+    std::size_t catch_strnlen( const char* str, std::size_t n ) {
+        auto ret = std::char_traits<char>::find( str, n, '\0' );
+        if ( ret != nullptr ) { return static_cast<std::size_t>( ret - str ); }
+        return n;
+    }
+
+    std::string formatTimeT(std::time_t time) {
+#ifdef _MSC_VER
+        std::tm timeInfo = {};
+        const auto err = gmtime_s( &timeInfo, &time );
+        if ( err ) {
+            return "gmtime from provided timepoint has failed. This "
+                   "happens e.g. with pre-1970 dates using Microsoft libc";
+        }
+#else
+        std::tm* timeInfo = std::gmtime( &time );
+#endif
+
+        auto const timeStampSize = sizeof( "2017-01-16T17:06:45Z" );
+        char timeStamp[timeStampSize];
+        const char* const fmt = "%Y-%m-%dT%H:%M:%SZ";
+
+#ifdef _MSC_VER
+        std::strftime( timeStamp, timeStampSize, fmt, &timeInfo );
+#else
+        std::strftime( timeStamp, timeStampSize, fmt, timeInfo );
+#endif
+        return std::string( timeStamp, timeStampSize - 1 );
+    }
+
     std::string convertIntoString(StringRef string, bool escapeInvisibles) {
         std::string ret;
         // This is enough for the "don't escape invisibles" case, and a good

src/catch2/catch_tostring.hpp

@@ -8,7 +8,7 @@
 #ifndef CATCH_TOSTRING_HPP_INCLUDED
 #define CATCH_TOSTRING_HPP_INCLUDED
 
-
+#include <ctime>
 #include <vector>
 #include <cstddef>
 #include <type_traits>
@@ -40,13 +40,9 @@ namespace Catch {
 
     namespace Detail {
 
-        inline std::size_t catch_strnlen(const char *str, std::size_t n) {
-            auto ret = std::char_traits<char>::find(str, n, '\0');
-            if (ret != nullptr) {
-                return static_cast<std::size_t>(ret - str);
-            }
-            return n;
-        }
+        std::size_t catch_strnlen(const char *str, std::size_t n);
+
+        std::string formatTimeT( std::time_t time );
 
         constexpr StringRef unprintableString = "{?}"_sr;
 
@@ -411,44 +407,38 @@ namespace Catch {
 
 // Separate std::tuple specialization
 #if defined(CATCH_CONFIG_ENABLE_TUPLE_STRINGMAKER)
-#include <tuple>
+#    include <tuple>
+#    include <utility>
 namespace Catch {
     namespace Detail {
-        template<
-            typename Tuple,
-            std::size_t N = 0,
-            bool = (N < std::tuple_size<Tuple>::value)
-            >
-            struct TupleElementPrinter {
-            static void print(const Tuple& tuple, std::ostream& os) {
-                os << (N ? ", " : " ")
-                    << ::Catch::Detail::stringify(std::get<N>(tuple));
-                TupleElementPrinter<Tuple, N + 1>::print(tuple, os);
-            }
-        };
+        template <typename Tuple, std::size_t... Is>
+        void PrintTuple( const Tuple& tuple,
+                         std::ostream& os,
+                         std::index_sequence<Is...> ) {
+            // 1 + Account for when the tuple is empty
+            char a[1 + sizeof...( Is )] = {
+                ( ( os << ( Is ? ", " : " " )
+                       << ::Catch::Detail::stringify( std::get<Is>( tuple ) ) ),
+                  '\0' )... };
+            (void)a;
+        }
 
-        template<
-            typename Tuple,
-            std::size_t N
-        >
-            struct TupleElementPrinter<Tuple, N, false> {
-            static void print(const Tuple&, std::ostream&) {}
-        };
+    } // namespace Detail
 
-    }
-
-
-    template<typename ...Types>
+    template <typename... Types>
     struct StringMaker<std::tuple<Types...>> {
-        static std::string convert(const std::tuple<Types...>& tuple) {
+        static std::string convert( const std::tuple<Types...>& tuple ) {
             ReusableStringStream rss;
             rss << '{';
-            Detail::TupleElementPrinter<std::tuple<Types...>>::print(tuple, rss.get());
+            Detail::PrintTuple(
+                tuple,
+                rss.get(),
+                std::make_index_sequence<sizeof...( Types )>{} );
             rss << " }";
             return rss.str();
         }
     };
-}
+} // namespace Catch
 #endif // CATCH_CONFIG_ENABLE_TUPLE_STRINGMAKER
 
 #if defined(CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER) && defined(CATCH_CONFIG_CPP17_VARIANT)
@@ -635,28 +625,7 @@ struct ratio_string<std::milli> {
             const auto systemish = std::chrono::time_point_cast<
                 std::chrono::system_clock::duration>( time_point );
             const auto as_time_t = std::chrono::system_clock::to_time_t( systemish );
-
-#ifdef _MSC_VER
-            std::tm timeInfo = {};
-            const auto err = gmtime_s( &timeInfo, &as_time_t );
-            if ( err ) {
-                return "gmtime from provided timepoint has failed. This "
-                       "happens e.g. with pre-1970 dates using Microsoft libc";
-            }
-#else
-            std::tm* timeInfo = std::gmtime( &as_time_t );
-#endif
-
-            auto const timeStampSize = sizeof("2017-01-16T17:06:45Z");
-            char timeStamp[timeStampSize];
-            const char * const fmt = "%Y-%m-%dT%H:%M:%SZ";
-
-#ifdef _MSC_VER
-            std::strftime(timeStamp, timeStampSize, fmt, &timeInfo);
-#else
-            std::strftime(timeStamp, timeStampSize, fmt, timeInfo);
-#endif
-            return std::string(timeStamp, timeStampSize - 1);
+            return ::Catch::Detail::formatTimeT( as_time_t );
         }
     };
 }

src/catch2/internal/catch_lifetimebound.hpp

@@ -0,0 +1,24 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+#ifndef CATCH_LIFETIMEBOUND_HPP_INCLUDED
+#define CATCH_LIFETIMEBOUND_HPP_INCLUDED
+
+#if !defined( __has_cpp_attribute )
+#    define CATCH_ATTR_LIFETIMEBOUND
+#elif __has_cpp_attribute( msvc::lifetimebound )
+#    define CATCH_ATTR_LIFETIMEBOUND [[msvc::lifetimebound]]
+#elif __has_cpp_attribute( clang::lifetimebound )
+#    define CATCH_ATTR_LIFETIMEBOUND [[clang::lifetimebound]]
+#elif __has_cpp_attribute( lifetimebound )
+#    define CATCH_ATTR_LIFETIMEBOUND [[lifetimebound]]
+#else
+#    define CATCH_ATTR_LIFETIMEBOUND
+#endif
+
+#endif // CATCH_LIFETIMEBOUND_HPP_INCLUDED

src/catch2/internal/catch_string_manip.hpp

@@ -8,6 +8,7 @@
 #ifndef CATCH_STRING_MANIP_HPP_INCLUDED
 #define CATCH_STRING_MANIP_HPP_INCLUDED
 
+#include <catch2/internal/catch_lifetimebound.hpp>
 #include <catch2/internal/catch_stringref.hpp>
 
 #include <cstdint>
@@ -28,10 +29,10 @@ namespace Catch {
     //! Returns a new string without whitespace at the start/end
     std::string trim( std::string const& str );
     //! Returns a substring of the original ref without whitespace. Beware lifetimes!
-    StringRef trim(StringRef ref);
+    StringRef trim( StringRef ref CATCH_ATTR_LIFETIMEBOUND );
 
     // !!! Be aware, returns refs into original string - make sure original string outlives them
-    std::vector<StringRef> splitStringRef( StringRef str, char delimiter );
+    std::vector<StringRef> splitStringRef( StringRef str CATCH_ATTR_LIFETIMEBOUND, char delimiter );
     bool replaceInPlace( std::string& str, std::string const& replaceThis, std::string const& withThis );
 
     /**
@@ -49,7 +50,7 @@ namespace Catch {
         StringRef m_label;
 
     public:
-        constexpr pluralise(std::uint64_t count, StringRef label):
+        constexpr pluralise(std::uint64_t count, StringRef label CATCH_ATTR_LIFETIMEBOUND):
             m_count(count),
             m_label(label)
         {}

src/catch2/internal/catch_stringref.hpp

@@ -8,11 +8,12 @@
 #ifndef CATCH_STRINGREF_HPP_INCLUDED
 #define CATCH_STRINGREF_HPP_INCLUDED
 
+#include <catch2/internal/catch_lifetimebound.hpp>
+
 #include <cstddef>
 #include <string>
 #include <iosfwd>
 #include <cassert>
-
 #include <cstring>
 
 namespace Catch {
@@ -36,14 +37,16 @@ namespace Catch {
     public: // construction
         constexpr StringRef() noexcept = default;
 
-        StringRef( char const* rawChars ) noexcept;
+        StringRef( char const* rawChars CATCH_ATTR_LIFETIMEBOUND ) noexcept;
 
-        constexpr StringRef( char const* rawChars, size_type size ) noexcept
+        constexpr StringRef( char const* rawChars CATCH_ATTR_LIFETIMEBOUND,
+                             size_type size ) noexcept
         :   m_start( rawChars ),
             m_size( size )
         {}
 
-        StringRef( std::string const& stdString ) noexcept
+        StringRef(
+            std::string const& stdString CATCH_ATTR_LIFETIMEBOUND ) noexcept
         :   m_start( stdString.c_str() ),
             m_size( stdString.size() )
         {}
@@ -89,7 +92,7 @@ namespace Catch {
         }
 
         // Returns the current start pointer. May not be null-terminated.
-        constexpr char const* data() const noexcept {
+        constexpr char const* data() const noexcept CATCH_ATTR_LIFETIMEBOUND {
             return m_start;
         }
 

src/catch2/internal/catch_test_case_tracker.hpp

@@ -8,6 +8,7 @@
 #ifndef CATCH_TEST_CASE_TRACKER_HPP_INCLUDED
 #define CATCH_TEST_CASE_TRACKER_HPP_INCLUDED
 
+#include <catch2/internal/catch_lifetimebound.hpp>
 #include <catch2/internal/catch_source_line_info.hpp>
 #include <catch2/internal/catch_unique_ptr.hpp>
 #include <catch2/internal/catch_stringref.hpp>
@@ -48,7 +49,7 @@ namespace TestCaseTracking {
         StringRef name;
         SourceLineInfo location;
 
-        constexpr NameAndLocationRef( StringRef name_,
+        constexpr NameAndLocationRef( StringRef name_ CATCH_ATTR_LIFETIMEBOUND,
                                       SourceLineInfo location_ ):
             name( name_ ), location( location_ ) {}
 

src/catch2/matchers/catch_matchers.hpp

@@ -10,6 +10,7 @@
 
 #include <catch2/matchers/internal/catch_matchers_impl.hpp>
 #include <catch2/internal/catch_move_and_forward.hpp>
+#include <catch2/internal/catch_lifetimebound.hpp>
 
 #include <string>
 #include <vector>
@@ -79,11 +80,15 @@ namespace Matchers {
                 return description;
             }
 
-            friend MatchAllOf operator&& (MatchAllOf&& lhs, MatcherBase<ArgT> const& rhs) {
+            friend MatchAllOf operator&&( MatchAllOf&& lhs,
+                                          MatcherBase<ArgT> const& rhs
+                                              CATCH_ATTR_LIFETIMEBOUND ) {
                 lhs.m_matchers.push_back(&rhs);
                 return CATCH_MOVE(lhs);
             }
-            friend MatchAllOf operator&& (MatcherBase<ArgT> const& lhs, MatchAllOf&& rhs) {
+            friend MatchAllOf
+            operator&&( MatcherBase<ArgT> const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                        MatchAllOf&& rhs ) {
                 rhs.m_matchers.insert(rhs.m_matchers.begin(), &lhs);
                 return CATCH_MOVE(rhs);
             }
@@ -131,11 +136,15 @@ namespace Matchers {
                 return description;
             }
 
-            friend MatchAnyOf operator|| (MatchAnyOf&& lhs, MatcherBase<ArgT> const& rhs) {
+            friend MatchAnyOf operator||( MatchAnyOf&& lhs,
+                                          MatcherBase<ArgT> const& rhs
+                                              CATCH_ATTR_LIFETIMEBOUND ) {
                 lhs.m_matchers.push_back(&rhs);
                 return CATCH_MOVE(lhs);
             }
-            friend MatchAnyOf operator|| (MatcherBase<ArgT> const& lhs, MatchAnyOf&& rhs) {
+            friend MatchAnyOf
+            operator||( MatcherBase<ArgT> const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                        MatchAnyOf&& rhs ) {
                 rhs.m_matchers.insert(rhs.m_matchers.begin(), &lhs);
                 return CATCH_MOVE(rhs);
             }
@@ -155,7 +164,8 @@ namespace Matchers {
             MatcherBase<ArgT> const& m_underlyingMatcher;
 
         public:
-            explicit MatchNotOf( MatcherBase<ArgT> const& underlyingMatcher ):
+            explicit MatchNotOf( MatcherBase<ArgT> const& underlyingMatcher
+                                     CATCH_ATTR_LIFETIMEBOUND ):
                 m_underlyingMatcher( underlyingMatcher )
             {}
 
@@ -171,16 +181,22 @@ namespace Matchers {
     } // namespace Detail
 
     template <typename T>
-    Detail::MatchAllOf<T> operator&& (MatcherBase<T> const& lhs, MatcherBase<T> const& rhs) {
+    Detail::MatchAllOf<T>
+    operator&&( MatcherBase<T> const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatcherBase<T> const& rhs CATCH_ATTR_LIFETIMEBOUND ) {
         return Detail::MatchAllOf<T>{} && lhs && rhs;
     }
+
     template <typename T>
-    Detail::MatchAnyOf<T> operator|| (MatcherBase<T> const& lhs, MatcherBase<T> const& rhs) {
+    Detail::MatchAnyOf<T>
+    operator||( MatcherBase<T> const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatcherBase<T> const& rhs CATCH_ATTR_LIFETIMEBOUND ) {
         return Detail::MatchAnyOf<T>{} || lhs || rhs;
     }
 
     template <typename T>
-    Detail::MatchNotOf<T> operator! (MatcherBase<T> const& matcher) {
+    Detail::MatchNotOf<T>
+    operator!( MatcherBase<T> const& matcher CATCH_ATTR_LIFETIMEBOUND ) {
         return Detail::MatchNotOf<T>{ matcher };
     }
 

src/catch2/matchers/catch_matchers_templated.hpp

@@ -11,6 +11,7 @@
 #include <catch2/matchers/catch_matchers.hpp>
 #include <catch2/internal/catch_stringref.hpp>
 #include <catch2/internal/catch_move_and_forward.hpp>
+#include <catch2/internal/catch_lifetimebound.hpp>
 #include <catch2/internal/catch_logical_traits.hpp>
 
 #include <array>
@@ -114,7 +115,8 @@ namespace Matchers {
             MatchAllOfGeneric(MatchAllOfGeneric&&) = default;
             MatchAllOfGeneric& operator=(MatchAllOfGeneric&&) = default;
 
-            MatchAllOfGeneric(MatcherTs const&... matchers) : m_matchers{ {std::addressof(matchers)...} } {}
+            MatchAllOfGeneric(MatcherTs const&... matchers CATCH_ATTR_LIFETIMEBOUND)
+                : m_matchers{ {std::addressof(matchers)...} } {}
             explicit MatchAllOfGeneric(std::array<void const*, sizeof...(MatcherTs)> matchers) : m_matchers{matchers} {}
 
             template<typename Arg>
@@ -136,8 +138,8 @@ namespace Matchers {
             template<typename... MatchersRHS>
             friend
             MatchAllOfGeneric<MatcherTs..., MatchersRHS...> operator && (
-                    MatchAllOfGeneric<MatcherTs...>&& lhs,
-                    MatchAllOfGeneric<MatchersRHS...>&& rhs) {
+                MatchAllOfGeneric<MatcherTs...>&& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatchAllOfGeneric<MatchersRHS...>&& rhs CATCH_ATTR_LIFETIMEBOUND ) {
                 return MatchAllOfGeneric<MatcherTs..., MatchersRHS...>{array_cat(CATCH_MOVE(lhs.m_matchers), CATCH_MOVE(rhs.m_matchers))};
             }
 
@@ -145,8 +147,8 @@ namespace Matchers {
             template<typename MatcherRHS>
             friend std::enable_if_t<is_matcher_v<MatcherRHS>,
             MatchAllOfGeneric<MatcherTs..., MatcherRHS>> operator && (
-                    MatchAllOfGeneric<MatcherTs...>&& lhs,
-                    MatcherRHS const& rhs) {
+                MatchAllOfGeneric<MatcherTs...>&& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatcherRHS const& rhs CATCH_ATTR_LIFETIMEBOUND ) {
                 return MatchAllOfGeneric<MatcherTs..., MatcherRHS>{array_cat(CATCH_MOVE(lhs.m_matchers), static_cast<void const*>(&rhs))};
             }
 
@@ -154,8 +156,8 @@ namespace Matchers {
             template<typename MatcherLHS>
             friend std::enable_if_t<is_matcher_v<MatcherLHS>,
             MatchAllOfGeneric<MatcherLHS, MatcherTs...>> operator && (
-                    MatcherLHS const& lhs,
-                    MatchAllOfGeneric<MatcherTs...>&& rhs) {
+                MatcherLHS const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatchAllOfGeneric<MatcherTs...>&& rhs CATCH_ATTR_LIFETIMEBOUND ) {
                 return MatchAllOfGeneric<MatcherLHS, MatcherTs...>{array_cat(static_cast<void const*>(std::addressof(lhs)), CATCH_MOVE(rhs.m_matchers))};
             }
         };
@@ -169,7 +171,8 @@ namespace Matchers {
             MatchAnyOfGeneric(MatchAnyOfGeneric&&) = default;
             MatchAnyOfGeneric& operator=(MatchAnyOfGeneric&&) = default;
 
-            MatchAnyOfGeneric(MatcherTs const&... matchers) : m_matchers{ {std::addressof(matchers)...} } {}
+            MatchAnyOfGeneric(MatcherTs const&... matchers CATCH_ATTR_LIFETIMEBOUND)
+                : m_matchers{ {std::addressof(matchers)...} } {}
             explicit MatchAnyOfGeneric(std::array<void const*, sizeof...(MatcherTs)> matchers) : m_matchers{matchers} {}
 
             template<typename Arg>
@@ -190,8 +193,8 @@ namespace Matchers {
             //! Avoids type nesting for `GenericAnyOf || GenericAnyOf` case
             template<typename... MatchersRHS>
             friend MatchAnyOfGeneric<MatcherTs..., MatchersRHS...> operator || (
-                    MatchAnyOfGeneric<MatcherTs...>&& lhs,
-                    MatchAnyOfGeneric<MatchersRHS...>&& rhs) {
+                MatchAnyOfGeneric<MatcherTs...>&& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatchAnyOfGeneric<MatchersRHS...>&& rhs CATCH_ATTR_LIFETIMEBOUND ) {
                 return MatchAnyOfGeneric<MatcherTs..., MatchersRHS...>{array_cat(CATCH_MOVE(lhs.m_matchers), CATCH_MOVE(rhs.m_matchers))};
             }
 
@@ -199,8 +202,8 @@ namespace Matchers {
             template<typename MatcherRHS>
             friend std::enable_if_t<is_matcher_v<MatcherRHS>,
             MatchAnyOfGeneric<MatcherTs..., MatcherRHS>> operator || (
-                    MatchAnyOfGeneric<MatcherTs...>&& lhs,
-                    MatcherRHS const& rhs) {
+                    MatchAnyOfGeneric<MatcherTs...>&& lhs CATCH_ATTR_LIFETIMEBOUND,
+                    MatcherRHS const& rhs CATCH_ATTR_LIFETIMEBOUND ) {
                 return MatchAnyOfGeneric<MatcherTs..., MatcherRHS>{array_cat(CATCH_MOVE(lhs.m_matchers), static_cast<void const*>(std::addressof(rhs)))};
             }
 
@@ -208,8 +211,8 @@ namespace Matchers {
             template<typename MatcherLHS>
             friend std::enable_if_t<is_matcher_v<MatcherLHS>,
             MatchAnyOfGeneric<MatcherLHS, MatcherTs...>> operator || (
-                MatcherLHS const& lhs,
-                MatchAnyOfGeneric<MatcherTs...>&& rhs) {
+                MatcherLHS const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatchAnyOfGeneric<MatcherTs...>&& rhs CATCH_ATTR_LIFETIMEBOUND) {
                 return MatchAnyOfGeneric<MatcherLHS, MatcherTs...>{array_cat(static_cast<void const*>(std::addressof(lhs)), CATCH_MOVE(rhs.m_matchers))};
             }
         };
@@ -225,7 +228,8 @@ namespace Matchers {
             MatchNotOfGeneric(MatchNotOfGeneric&&) = default;
             MatchNotOfGeneric& operator=(MatchNotOfGeneric&&) = default;
 
-            explicit MatchNotOfGeneric(MatcherT const& matcher) : m_matcher{matcher} {}
+            explicit MatchNotOfGeneric(MatcherT const& matcher CATCH_ATTR_LIFETIMEBOUND)
+                : m_matcher{matcher} {}
 
             template<typename Arg>
             bool match(Arg&& arg) const {
@@ -237,7 +241,9 @@ namespace Matchers {
             }
 
             //! Negating negation can just unwrap and return underlying matcher
-            friend MatcherT const& operator ! (MatchNotOfGeneric<MatcherT> const& matcher) {
+            friend MatcherT const&
+            operator!( MatchNotOfGeneric<MatcherT> const& matcher
+                           CATCH_ATTR_LIFETIMEBOUND ) {
                 return matcher.m_matcher;
             }
         };
@@ -247,20 +253,22 @@ namespace Matchers {
     // compose only generic matchers
     template<typename MatcherLHS, typename MatcherRHS>
     std::enable_if_t<Detail::are_generic_matchers_v<MatcherLHS, MatcherRHS>, Detail::MatchAllOfGeneric<MatcherLHS, MatcherRHS>>
-        operator && (MatcherLHS const& lhs, MatcherRHS const& rhs) {
+    operator&&( MatcherLHS const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatcherRHS const& rhs CATCH_ATTR_LIFETIMEBOUND ) {
         return { lhs, rhs };
     }
 
     template<typename MatcherLHS, typename MatcherRHS>
     std::enable_if_t<Detail::are_generic_matchers_v<MatcherLHS, MatcherRHS>, Detail::MatchAnyOfGeneric<MatcherLHS, MatcherRHS>>
-        operator || (MatcherLHS const& lhs, MatcherRHS const& rhs) {
+    operator||( MatcherLHS const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatcherRHS const& rhs CATCH_ATTR_LIFETIMEBOUND ) {
         return { lhs, rhs };
     }
 
     //! Wrap provided generic matcher in generic negator
     template<typename MatcherT>
     std::enable_if_t<Detail::is_generic_matcher_v<MatcherT>, Detail::MatchNotOfGeneric<MatcherT>>
-        operator ! (MatcherT const& matcher) {
+    operator!( MatcherT const& matcher CATCH_ATTR_LIFETIMEBOUND ) {
         return Detail::MatchNotOfGeneric<MatcherT>{matcher};
     }
 
@@ -268,25 +276,29 @@ namespace Matchers {
     // compose mixed generic and non-generic matchers
     template<typename MatcherLHS, typename ArgRHS>
     std::enable_if_t<Detail::is_generic_matcher_v<MatcherLHS>, Detail::MatchAllOfGeneric<MatcherLHS, MatcherBase<ArgRHS>>>
-        operator && (MatcherLHS const& lhs, MatcherBase<ArgRHS> const& rhs) {
+    operator&&( MatcherLHS const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatcherBase<ArgRHS> const& rhs CATCH_ATTR_LIFETIMEBOUND ) {
         return { lhs, rhs };
     }
 
     template<typename ArgLHS, typename MatcherRHS>
     std::enable_if_t<Detail::is_generic_matcher_v<MatcherRHS>, Detail::MatchAllOfGeneric<MatcherBase<ArgLHS>, MatcherRHS>>
-        operator && (MatcherBase<ArgLHS> const& lhs, MatcherRHS const& rhs) {
+    operator&&( MatcherBase<ArgLHS> const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatcherRHS const& rhs CATCH_ATTR_LIFETIMEBOUND ) {
         return { lhs, rhs };
     }
 
     template<typename MatcherLHS, typename ArgRHS>
     std::enable_if_t<Detail::is_generic_matcher_v<MatcherLHS>, Detail::MatchAnyOfGeneric<MatcherLHS, MatcherBase<ArgRHS>>>
-        operator || (MatcherLHS const& lhs, MatcherBase<ArgRHS> const& rhs) {
+    operator||( MatcherLHS const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatcherBase<ArgRHS> const& rhs CATCH_ATTR_LIFETIMEBOUND ) {
         return { lhs, rhs };
     }
 
     template<typename ArgLHS, typename MatcherRHS>
     std::enable_if_t<Detail::is_generic_matcher_v<MatcherRHS>, Detail::MatchAnyOfGeneric<MatcherBase<ArgLHS>, MatcherRHS>>
-        operator || (MatcherBase<ArgLHS> const& lhs, MatcherRHS const& rhs) {
+    operator||( MatcherBase<ArgLHS> const& lhs CATCH_ATTR_LIFETIMEBOUND,
+                MatcherRHS const& rhs CATCH_ATTR_LIFETIMEBOUND ) {
         return { lhs, rhs };
     }
 

src/catch2/meson.build

@@ -105,6 +105,7 @@ internal_headers = [
   'internal/catch_jsonwriter.hpp',
   'internal/catch_lazy_expr.hpp',
   'internal/catch_leak_detector.hpp',
+  'internal/catch_lifetimebound.hpp',
   'internal/catch_list.hpp',
   'internal/catch_logical_traits.hpp',
   'internal/catch_message_info.hpp',