chore: import upstream snapshot with attribution

examples/cpp/log_file/main.cpp

@@ -0,0 +1,80 @@
+#include <filesystem>
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <string>
+
+#include <rerun.hpp>
+#include <rerun/third_party/cxxopts.hpp>
+
+int main(int argc, char** argv) {
+    // Create a new `RecordingStream` which sends data over gRPC to the viewer process.
+    const auto rec = rerun::RecordingStream("rerun_example_log_file");
+
+    cxxopts::Options options(
+        "rerun_example_log_file",
+        "Demonstrates how to log any file from the SDK using the `Importer` machinery."
+    );
+
+    // clang-format off
+    options.add_options()
+      ("h,help", "Print usage")
+      // Rerun
+      ("spawn", "Start a new Rerun Viewer process and feed it data in real-time")
+      ("connect", "Connects and sends the logged data to a remote Rerun viewer")
+      ("save", "Log data to an rrd file", cxxopts::value<std::string>())
+      ("stdout", "Log data to standard output, to be piped into a Rerun Viewer")
+      // Example
+      ("from-contents", "Log the contents of the file directly (files only -- not supported by external loaders)", cxxopts::value<bool>()->default_value("false"))
+      ("filepaths", "The filepaths to be loaded and logged", cxxopts::value<std::vector<std::string>>())
+    ;
+    // clang-format on
+
+    options.parse_positional({"filepaths"});
+
+    auto args = options.parse(argc, argv);
+
+    if (args.count("help")) {
+        std::cout << options.help() << std::endl;
+        exit(0);
+    }
+
+    // TODO(#4602): need common rerun args helper library
+    if (args["spawn"].as<bool>()) {
+        rec.spawn().exit_on_failure();
+    } else if (args["connect"].as<bool>()) {
+        rec.connect_grpc().exit_on_failure();
+    } else if (args["stdout"].as<bool>()) {
+        rec.to_stdout().exit_on_failure();
+    } else if (args.count("save")) {
+        rec.save(args["save"].as<std::string>()).exit_on_failure();
+    } else {
+        rec.spawn().exit_on_failure();
+    }
+
+    const auto from_contents = args["from-contents"].as<bool>();
+    if (args.count("filepaths")) {
+        const auto filepaths = args["filepaths"].as<std::vector<std::string>>();
+        for (const auto& filepath : filepaths) {
+            if (!from_contents) {
+                // Either log the file using its path…
+                rec.log_file_from_path(filepath, "log_file_example");
+            } else {
+                // …or using its contents if you already have them loaded for some reason.
+                if (std::filesystem::is_regular_file(filepath)) {
+                    std::ifstream file(filepath);
+                    std::stringstream contents;
+                    contents << file.rdbuf();
+
+                    const auto data = contents.str();
+                    rec.log_file_from_contents(
+                        filepath,
+                        reinterpret_cast<const std::byte*>(data.c_str()),
+                        data.size(),
+                        "log_file_example"
+                    );
+                }
+            }
+        }
+    }
+}