Switched to header only spdlog for better portability

thirdparty/spdlog/sinks/null_sink.h

@@ -0,0 +1,44 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/details/null_mutex.h>
+#include <spdlog/sinks/base_sink.h>
+#include <spdlog/details/synchronous_factory.h>
+
+#include <mutex>
+
+namespace spdlog {
+namespace sinks {
+
+template<typename Mutex>
+class null_sink : public base_sink<Mutex>
+{
+protected:
+    void sink_it_(const details::log_msg &) override {}
+    void flush_() override {}
+};
+
+using null_sink_mt = null_sink<details::null_mutex>;
+using null_sink_st = null_sink<details::null_mutex>;
+
+} // namespace sinks
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> null_logger_mt(const std::string &logger_name)
+{
+    auto null_logger = Factory::template create<sinks::null_sink_mt>(logger_name);
+    null_logger->set_level(level::off);
+    return null_logger;
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> null_logger_st(const std::string &logger_name)
+{
+    auto null_logger = Factory::template create<sinks::null_sink_st>(logger_name);
+    null_logger->set_level(level::off);
+    return null_logger;
+}
+
+} // namespace spdlog