Make std::filesystem::path conversion to/from UTF-8 encoded string ex…

…plicit. Signed-off-by: Richard Musil <[email protected]>
nlohmann · Jan 26, 2025 · a395539 · a395539
1 parent d0789e3
commit a395539
Show file tree

Hide file tree

Showing 4 changed files with 1,446 additions and 1,476 deletions.
diff --git a/include/nlohmann/detail/conversions/from_json.hpp b/include/nlohmann/detail/conversions/from_json.hpp
@@ -539,7 +539,12 @@ inline void from_json(const BasicJsonType& j, std_fs::path& p)
     {
         JSON_THROW(type_error::create(302, concat("type must be string, but is ", j.type_name()), &j));
     }
-    p = *j.template get_ptr<const typename BasicJsonType::string_t*>();
+    const auto& s = *j.template get_ptr<const typename BasicJsonType::string_t*>();
+#ifdef JSON_HAS_CPP_20
+    p = std_fs::path(std::u8string_view(reinterpret_cast<const char8_t*>(s.data()), s.size()));
+#else
+    p = std_fs::u8path(s); // accepts UTF-8 encoded std::string in C++17, deprecated in C++20
+#endif
 }
 #endif
 

diff --git a/include/nlohmann/detail/conversions/to_json.hpp b/include/nlohmann/detail/conversions/to_json.hpp
@@ -443,7 +443,12 @@ inline void to_json(BasicJsonType& j, const T& t)
 template<typename BasicJsonType>
 inline void to_json(BasicJsonType& j, const std_fs::path& p)
 {
-    j = p.string();
+#ifdef JSON_HAS_CPP_20
+    const std::u8string s = p.u8string();
+    j = std::string(s.begin(), s.end());
+#else
+    j = p.u8string(); // returns std::string in C++17
+#endif
 }
 #endif
 

diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
@@ -5319,7 +5319,12 @@ inline void from_json(const BasicJsonType& j, std_fs::path& p)
     {
         JSON_THROW(type_error::create(302, concat("type must be string, but is ", j.type_name()), &j));
     }
-    p = *j.template get_ptr<const typename BasicJsonType::string_t*>();
+    const auto& s = *j.template get_ptr<const typename BasicJsonType::string_t*>();
+#ifdef JSON_HAS_CPP_20
+    p = std_fs::path(std::u8string_view(reinterpret_cast<const char8_t*>(s.data()), s.size()));
+#else
+    p = std_fs::u8path(s); // accepts UTF-8 encoded std::string in C++17, deprecated in C++20
+#endif
 }
 #endif
 
@@ -6080,7 +6085,12 @@ inline void to_json(BasicJsonType& j, const T& t)
 template<typename BasicJsonType>
 inline void to_json(BasicJsonType& j, const std_fs::path& p)
 {
-    j = p.string();
+#ifdef JSON_HAS_CPP_20
+    const std::u8string s = p.u8string();
+    j = std::string(s.begin(), s.end());
+#else
+    j = p.u8string(); // returns std::string in C++17
+#endif
 }
 #endif