test: guard rotation test for C++11

Author: LimiNode

tests/file_logger_rotation_test.cpp

@@ -2,16 +2,28 @@
 #include <LogIt.hpp>
 #include <fstream>
 #include <string>
+#if __cplusplus >= 201703L
 #include <filesystem>
+#endif
 
 int main() {
     LOGIT_ADD_FILE_LOGGER_WITH_ROTATION(".", true, 30, "%v", 20, 10);
     const std::string msg = "0123456789"; // 10 bytes
     LOGIT_INFO(msg);
     LOGIT_INFO(msg);
     LOGIT_WAIT();
+#if __cplusplus >= 201703L
     std::filesystem::path current = LOGIT_GET_LAST_FILE_PATH(0);
     std::filesystem::path rotated = current;
     rotated.replace_filename(current.stem().string() + ".001.log");
     return std::filesystem::exists(rotated) ? 0 : 1;
+#else
+    std::string current = LOGIT_GET_LAST_FILE_PATH(0);
+    std::string rotated = current;
+    size_t pos = rotated.rfind(".log");
+    if (pos == std::string::npos) return 1;
+    rotated.insert(pos, ".001");
+    std::ifstream f(rotated.c_str());
+    return f.good() ? 0 : 1;
+#endif
 }