A couple more review fixes to make copilot happy

Author: raulcd

cpp/src/arrow/filesystem/filesystem.h

@@ -593,10 +593,9 @@ Result<std::shared_ptr<FileSystem>> FileSystemFromUri(const std::string& uri,
 ///            The expected type is specific to the backend and
 ///            option name.
 ///            Options are forwarded to schemes dispatched through a registered
-///            FileSystemFactory. A registered factory that does not support options
-///            (currently "s3") returns NotImplemented for non-empty options.
-///            Schemes not handled by a registered factory will also return
-///            NotImplemented for non-empty options.
+///            FileSystemFactory. Non-empty options return NotImplemented for a registered
+///            FileSystemFactory that does not support them or for schemes not handled by
+///            a registered factory.
 /// \param[out] out_path (optional) Path inside the filesystem.
 /// \return out_fs FileSystem instance.
 ARROW_EXPORT
@@ -634,11 +633,9 @@ Result<std::shared_ptr<FileSystem>> FileSystemFromUri(const std::string& uri,
 ///            The expected type is specific to the backend and
 ///            option name.
 ///            Options are forwarded to schemes dispatched through a registered
-///            FileSystemFactory. A registered factory that does not support options
-///            (currently "s3") returns NotImplemented for non-empty options.
-///            Schemes not handled by a registered factory will also return
-///            NotImplemented for non-empty options.
-/// \param[in] io_context an IOContext which will be associated with the filesystem
+///            FileSystemFactory. Non-empty options return NotImplemented for a registered
+///            FileSystemFactory that does not support them or for schemes not handled by
+///            a registered factory.
 /// \param[out] out_path (optional) Path inside the filesystem.
 /// \return out_fs FileSystem instance.
 ARROW_EXPORT

cpp/src/arrow/testing/examplefs.cc

@@ -40,14 +40,16 @@ auto kExampleFileSystemModule = ARROW_REGISTER_FILESYSTEM(
       for (const auto& [key, value] : options) {
         EXPECT_TRUE(value.has_value());
         if (key == "example_option_string") {
-          EXPECT_TRUE(value.type() == typeid(std::string));
-          if (out_path != nullptr) {
-            *out_path += "/" + std::any_cast<std::string>(value);
+          if (const auto* s = std::any_cast<std::string>(&value)) {
+            if (out_path != nullptr) *out_path += "/" + *s;
+          } else {
+            ADD_FAILURE() << "example_option_string has wrong type";
           }
         } else if (key == "example_option_int") {
-          EXPECT_TRUE(value.type() == typeid(int));
-          if (out_path != nullptr) {
-            *out_path += "/" + std::to_string(std::any_cast<int>(value));
+          if (const auto* i = std::any_cast<int>(&value)) {
+            if (out_path != nullptr) *out_path += "/" + std::to_string(*i);
+          } else {
+            ADD_FAILURE() << "example_option_int has wrong type";
           }
         } else if (key == "example_typed_option") {
           if (const auto* opt =