std::filesystem::path support

include/cereal/details/helpers.hpp

@@ -256,6 +256,8 @@ namespace cereal
           @internal */
       DeferredData( T && v ) : value(std::forward<T>(v)) {}
 
+      DeferredData(const DeferredData &) = default;
+
       Type value;
   };
 

include/cereal/types/filesystem.hpp

@@ -0,0 +1,62 @@
+/*! \file filesystem.hpp
+    \brief Support for types found in \<filesystem\>
+    \ingroup STLSupport */
+/*
+  Copyright (c) 2023, Francois Michaut
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+      * Redistributions of source code must retain the above copyright
+        notice, this list of conditions and the following disclaimer.
+      * Redistributions in binary form must reproduce the above copyright
+        notice, this list of conditions and the following disclaimer in the
+        documentation and/or other materials provided with the distribution.
+      * Neither the name of the copyright holder nor the
+        names of its contributors may be used to endorse or promote products
+        derived from this software without specific prior written permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
+  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CEREAL_TYPES_FILESYSTEM_HPP_
+#define CEREAL_TYPES_FILESYSTEM_HPP_
+
+#include "cereal/cereal.hpp"
+#include "cereal/types/string.hpp"
+#include <filesystem>
+
+namespace cereal
+{
+  //! Serialization for std::filesystem::path types, if binary data is supported
+  template<class Archive> inline
+  typename std::enable_if<traits::is_output_serializable<BinaryData<std::filesystem::path::value_type>, Archive>::value, void>::type
+  CEREAL_SAVE_FUNCTION_NAME(Archive & ar, std::filesystem::path const & path)
+  {
+    // Save native path format
+    ar(path.native());
+  }
+
+  //! Serialization for std::filesystem::path types, if binary data is supported
+  template<class Archive> inline
+  typename std::enable_if<traits::is_input_serializable<BinaryData<std::filesystem::path::value_type>, Archive>::value, void>::type
+  CEREAL_LOAD_FUNCTION_NAME(Archive & ar, std::filesystem::path & path)
+  {
+    // load native path string
+    std::filesystem::path::string_type str;
+
+    ar(str);
+    path = std::move(str);
+  }
+} // namespace cereal
+
+#endif // CEREAL_TYPES_FILESYSTEM_HPP_

include/cereal/types/tuple.hpp

@@ -95,7 +95,7 @@ namespace cereal
       template <class Archive, class ... Types> inline
       static void apply( Archive & ar, std::tuple<Types...> & tuple )
       {
-        serialize<Height - 1>::template apply( ar, tuple );
+        serialize<Height - 1>::template apply<>( ar, tuple );
         ar( CEREAL_NVP_(tuple_element_name<Height - 1>::c_str(),
             std::get<Height - 1>( tuple )) );
       }
@@ -116,7 +116,7 @@ namespace cereal
   template <class Archive, class ... Types> inline
   void CEREAL_SERIALIZE_FUNCTION_NAME( Archive & ar, std::tuple<Types...> & tuple )
   {
-    tuple_detail::serialize<std::tuple_size<std::tuple<Types...>>::value>::template apply( ar, tuple );
+    tuple_detail::serialize<std::tuple_size<std::tuple<Types...>>::value>::template apply<>( ar, tuple );
   }
 } // namespace cereal
 

unittests/cpp17/filesystem.cpp

@@ -0,0 +1,57 @@
+/*
+  Copyright (c) 2025, Francois Michaut
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+      * Redistributions of source code must retain the above copyright
+        notice, this list of conditions and the following disclaimer.
+      * Redistributions in binary form must reproduce the above copyright
+        notice, this list of conditions and the following disclaimer in the
+        documentation and/or other materials provided with the distribution.
+      * Neither the name of the copyright holder nor the
+        names of its contributors may be used to endorse or promote products
+        derived from this software without specific prior written permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
+  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#define DOCTEST_CONFIG_IMPLEMENT_WITH_MAIN
+#include "filesystem.hpp"
+
+#ifdef CEREAL_HAS_CPP17
+
+TEST_SUITE_BEGIN("std_filesystem");
+
+TEST_CASE("binary_std_filesystem")
+{
+  test_std_filesystem_path<cereal::BinaryInputArchive, cereal::BinaryOutputArchive>();
+}
+
+TEST_CASE("portable_binary_std_filesystem")
+{
+  test_std_filesystem_path<cereal::PortableBinaryInputArchive, cereal::PortableBinaryOutputArchive>();
+}
+
+TEST_CASE("xml_std_filesystem")
+{
+  test_std_filesystem_path<cereal::XMLInputArchive, cereal::XMLOutputArchive>();
+}
+
+TEST_CASE("json_std_filesystem")
+{
+  test_std_filesystem_path<cereal::JSONInputArchive, cereal::JSONOutputArchive>();
+}
+
+TEST_SUITE_END();
+
+#endif // CEREAL_HAS_CPP17

unittests/cpp17/filesystem.hpp

@@ -0,0 +1,88 @@
+/*
+  Copyright (c) 2025, Francois Michaut
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+      * Redistributions of source code must retain the above copyright
+        notice, this list of conditions and the following disclaimer.
+      * Redistributions in binary form must reproduce the above copyright
+        notice, this list of conditions and the following disclaimer in the
+        documentation and/or other materials provided with the distribution.
+      * Neither the name of the copyright holder nor the
+        names of its contributors may be used to endorse or promote products
+        derived from this software without specific prior written permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
+  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef CEREAL_TEST_CPP17_FILESYSTEM_H_
+#define CEREAL_TEST_CPP17_FILESYSTEM_H_
+#include "../common.hpp"
+
+#ifdef CEREAL_HAS_CPP17
+
+#include <cereal/types/filesystem.hpp>
+
+template <class IArchive, class OArchive> inline
+void test_std_filesystem_path()
+{
+  std::random_device rd;
+  std::mt19937 gen(rd());
+
+  using char_type = std::filesystem::path::value_type;
+
+  for(size_t i=0; i<100; ++i)
+  {
+
+    std::filesystem::path path_a = random_basic_string<char_type>(gen);
+    std::filesystem::path path_b = random_basic_string<char_type>(gen);
+    std::filesystem::path path_c = random_basic_string<char_type>(gen);
+
+    std::filesystem::path o_path1 = random_basic_string<char_type>(gen);
+    std::filesystem::path o_path2 = "";
+    std::filesystem::path o_path3;
+    std::filesystem::path o_long_path = path_a / path_b / path_c;
+
+    std::ostringstream os;
+    {
+      OArchive oar(os);
+      oar(o_path1);
+      oar(o_path2);
+      oar(o_path3);
+      oar(o_long_path);
+    }
+
+    std::filesystem::path i_path1;
+    std::filesystem::path i_path2;
+    std::filesystem::path i_path3;
+    std::filesystem::path i_long_path;
+
+    std::istringstream is(os.str());
+    {
+      IArchive iar(is);
+
+      iar(i_path1);
+      iar(i_path2);
+      iar(i_path3);
+      iar(i_long_path);
+    }
+
+    CHECK_EQ(i_path1, o_path1);
+    CHECK_EQ(i_path2, o_path2);
+    CHECK_EQ(i_path3, o_path3);
+    CHECK_EQ(i_long_path, o_long_path);
+  }
+}
+
+#endif // CEREAL_HAS_CPP17
+#endif // CEREAL_TEST_CPP17_VARIANT_H_