added first working version of logger class

logger.cpp

@@ -0,0 +1,29 @@
+//
+// logger.cpp
+// libsclogging
+//
+// Created by Bob Polis at 2020-04-29
+// Copyright (c) 2020 SwiftCoder. All rights reserved.
+//
+
+#include "logger.hpp"
+
+using namespace sc;
+
+logger::logger(loglevel level) : _level(level) {
+}
+
+void logger::msg(loglevel level) {
+    if (level >= _level) {
+        if (_topcall) {
+            write_prefix();
+        } else {
+            _topcall = true;
+        }
+        std::cerr << '\n';
+    }
+}
+
+void logger::write_prefix() {
+    std::cerr << loglevel_desc(_level) << ": ";
+}

logger.hpp

@@ -0,0 +1,71 @@
+//
+// logger.hpp
+// libsclogging
+//
+// Created by Bob Polis at 2020-04-29
+// Copyright (c) 2020 SwiftCoder. All rights reserved.
+//
+
+#ifndef _logger_H_
+#define _logger_H_
+
+#include <iostream>
+
+namespace sc {
+
+    enum class loglevel {
+        undefined,
+        debug,
+        info,
+        warning,
+        error,
+        critical
+    };
+
+    constexpr bool operator>=(loglevel lhs, loglevel rhs) {
+        return static_cast<int>(lhs) >= static_cast<int>(rhs);
+    }
+
+    constexpr const char* loglevel_desc(loglevel lvl) {
+        switch (lvl) {
+            case loglevel::undefined: return "UNDEFINED"; break;
+            case loglevel::debug: return "DEBUG"; break;
+            case loglevel::info: return "INFO"; break;
+            case loglevel::warning: return "WARNING"; break;
+            case loglevel::error: return "ERROR"; break;
+            case loglevel::critical: return "CRITICAL"; break;
+        }
+        return "";
+    }
+   
+    class logger {
+        public:
+            logger(loglevel level);
+
+            void msg(loglevel level);
+           
+            template<typename T, typename... Args>
+            void msg(loglevel level, T value, Args... args) {
+                if (level >= _level) {
+                    if (_topcall) {
+                        _topcall = false;
+                        write_prefix();
+                    }
+                    std::cerr << value;
+                    msg(level, args...);
+                }
+            }
+
+            loglevel level() const { return _level; }
+            void level(loglevel level) { _level = level; }
+
+        private:
+            void write_prefix();
+           
+            loglevel _level {loglevel::info};
+            bool _topcall {true};
+    };
+
+}
+
+#endif // _logger_H_