diff --git a/README.md b/README.md
index 9a411fdd..52c71726 100644
--- a/README.md
+++ b/README.md
@@ -69,7 +69,7 @@ Time needed to log 1,000,000 lines in asynchronous mode, i.e. the time it takes
 
 ## Buck
 
-The test, examples and benchmarks can be run using [Buck](https://www.buckbuild.com):
+The tests, examples and benchmarks can be run using [Buck](https://www.buckbuild.com):
 
 ```bash
 buck run example/
@@ -131,11 +131,11 @@ int main(int, char*[])
         rotating_logger->info("This is another message with custom format");
 
 
-		// Runtime log levels
-		spd::set_level(spd::level::info); //Set global log level to info
-		console->debug("This message shold not be displayed!");
-		console->set_level(spd::level::debug); // Set specific logger's log level
-		console->debug("This message shold be displayed..");
+        // Runtime log levels
+	spd::set_level(spd::level::info); //Set global log level to info
+	console->debug("This message shold not be displayed!");
+	console->set_level(spd::level::debug); // Set specific logger's log level
+	console->debug("This message shold be displayed..");
 
         // Compile time log levels
         // define SPDLOG_DEBUG_ON or SPDLOG_TRACE_ON
@@ -159,13 +159,13 @@ int main(int, char*[])
         err_handler_example();
 
         // Apply a function on all registered loggers
-        spd::apply_all([&](std::shared_ptr<spdlog::logger> l)
+        spd::apply_all([&](std::shared_ptr<spd::logger> l)
         {
             l->info("End of example.");
         });
 
         // Release and close all loggers
-        spdlog::drop_all();
+        spd::drop_all();
     }
     // Exceptions will only be thrown upon failed logger or sink construction (not during logging)
     catch (const spd::spdlog_ex& ex)
@@ -178,7 +178,7 @@ int main(int, char*[])
 void async_example()
 {
     size_t q_size = 4096; //queue size must be power of 2
-    spdlog::set_async_mode(q_size);
+    spd::set_async_mode(q_size);
     auto async_file = spd::daily_logger_st("async_file_logger", "logs/async_log.txt");
     for (int i = 0; i < 100; ++i)
         async_file->info("Async message #{}", i);
@@ -216,7 +216,7 @@ void user_defined_example()
 //
 void err_handler_example()
 {
-	spdlog::set_error_handler([](const std::string& msg) {
+	spd::set_error_handler([](const std::string& msg) {
 		std::cerr << "my err handler: " << msg << std::endl;
 	});
 	// (or logger->set_error_handler(..) to set for specific logger)
diff --git a/include/spdlog/async_logger.h b/include/spdlog/async_logger.h
index 76d70a3d..a86d2190 100644
--- a/include/spdlog/async_logger.h
+++ b/include/spdlog/async_logger.h
@@ -31,7 +31,7 @@ namespace details
 class async_log_helper;
 }
 
-class async_logger :public logger
+class async_logger SPDLOG_FINAL :public logger
 {
 public:
     template<class It>
@@ -61,7 +61,7 @@ public:
                  const std::function<void()>& worker_teardown_cb = nullptr);
 
     //Wait for the queue to be empty, and flush synchronously
-    //Warning: this can potentialy last forever as we wait it to complete
+    //Warning: this can potentially last forever as we wait it to complete
     void flush() override;
 
     // Error handler
diff --git a/include/spdlog/common.h b/include/spdlog/common.h
index a0a227ef..e9fa372e 100644
--- a/include/spdlog/common.h
+++ b/include/spdlog/common.h
@@ -29,6 +29,11 @@
 #define SPDLOG_CONSTEXPR constexpr
 #endif
 
+// See tweakme.h
+#if !defined(SPDLOG_FINAL)
+#define SPDLOG_FINAL
+#endif
+
 #if defined(__GNUC__)  || defined(__clang__)
 #define SPDLOG_DEPRECATED __attribute__((deprecated))
 #elif defined(_MSC_VER)
diff --git a/include/spdlog/details/async_log_helper.h b/include/spdlog/details/async_log_helper.h
index 92a0f4cd..faa23cbe 100644
--- a/include/spdlog/details/async_log_helper.h
+++ b/include/spdlog/details/async_log_helper.h
@@ -9,8 +9,6 @@
 // If the internal queue of log messages reaches its max size,
 // then the client call will block until there is more room.
 //
-// If the back thread throws during logging, a spdlog::spdlog_ex exception
-// will be thrown in client's thread when tries to log the next message
 
 #pragma once
 
@@ -62,11 +60,15 @@ async_msg(async_msg&& other) SPDLOG_NOEXCEPT:
         logger_name(std::move(other.logger_name)),
                     level(std::move(other.level)),
                     time(std::move(other.time)),
+                    thread_id(other.thread_id),
                     txt(std::move(other.txt)),
                     msg_type(std::move(other.msg_type))
         {}
 
-        async_msg(async_msg_type m_type):msg_type(m_type)
+        async_msg(async_msg_type m_type):
+            level(level::info),
+            thread_id(0),
+            msg_type(m_type)
         {}
 
         async_msg& operator=(async_msg&& other) SPDLOG_NOEXCEPT
@@ -177,7 +179,7 @@ private:
 
     void handle_flush_interval(log_clock::time_point& now, log_clock::time_point& last_flush);
 
-    // sleep,yield or return immediatly using the time passed since last message as a hint
+    // sleep,yield or return immediately using the time passed since last message as a hint
     static void sleep_or_yield(const spdlog::log_clock::time_point& now, const log_clock::time_point& last_op_time);
 
     // wait until the queue is empty
diff --git a/include/spdlog/details/file_helper.h b/include/spdlog/details/file_helper.h
index 074d9b83..84ec722d 100644
--- a/include/spdlog/details/file_helper.h
+++ b/include/spdlog/details/file_helper.h
@@ -7,7 +7,6 @@
 
 // Helper class for file sink
 // When failing to open a file, retry several times(5) with small delay between the tries(10 ms)
-// Can be set to auto flush on every line
 // Throw spdlog_ex exception on errors
 
 #include <spdlog/details/os.h>
diff --git a/include/spdlog/details/logger_impl.h b/include/spdlog/details/logger_impl.h
index 5bb85f67..02ebc875 100644
--- a/include/spdlog/details/logger_impl.h
+++ b/include/spdlog/details/logger_impl.h
@@ -18,11 +18,11 @@ template<class It>
 inline spdlog::logger::logger(const std::string& logger_name, const It& begin, const It& end):
     _name(logger_name),
     _sinks(begin, end),
-    _formatter(std::make_shared<pattern_formatter>("%+"))
+    _formatter(std::make_shared<pattern_formatter>("%+")),
+    _level(level::info),
+    _flush_level(level::off),
+    _last_err_time(0)
 {
-    _level = level::info;
-    _flush_level = level::off;
-    _last_err_time = 0;
     _err_handler = [this](const std::string &msg)
     {
         this->_default_err_handler(msg);
@@ -195,6 +195,63 @@ inline void spdlog::logger::critical(const T& msg)
     log(level::critical, msg);
 }
 
+#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
+#include <codecvt>
+
+template <typename... Args>
+inline void spdlog::logger::log(level::level_enum lvl, const wchar_t* msg)
+{
+    std::wstring_convert<std::codecvt_utf8<wchar_t> > conv;
+
+    log(lvl, conv.to_bytes(msg));
+}
+
+template <typename... Args>
+inline void spdlog::logger::log(level::level_enum lvl, const wchar_t* fmt, const Args&... args)
+{
+    fmt::WMemoryWriter wWriter;
+
+    wWriter.write(fmt, args...);
+    log(lvl, wWriter.c_str());
+}
+
+template <typename... Args>
+inline void spdlog::logger::trace(const wchar_t* fmt, const Args&... args)
+{
+    log(level::trace, fmt, args...);
+}
+
+template <typename... Args>
+inline void spdlog::logger::debug(const wchar_t* fmt, const Args&... args)
+{
+    log(level::debug, fmt, args...);
+}
+
+template <typename... Args>
+inline void spdlog::logger::info(const wchar_t* fmt, const Args&... args)
+{
+    log(level::info, fmt, args...);
+}
+
+
+template <typename... Args>
+inline void spdlog::logger::warn(const wchar_t* fmt, const Args&... args)
+{
+    log(level::warn, fmt, args...);
+}
+
+template <typename... Args>
+inline void spdlog::logger::error(const wchar_t* fmt, const Args&... args)
+{
+    log(level::err, fmt, args...);
+}
+
+template <typename... Args>
+inline void spdlog::logger::critical(const wchar_t* fmt, const Args&... args)
+{
+    log(level::critical, fmt, args...);
+}
+#endif // SPDLOG_WCHAR_TO_UTF8_SUPPORT
 
 
 
diff --git a/include/spdlog/details/os.h b/include/spdlog/details/os.h
index b63ce667..91163efa 100644
--- a/include/spdlog/details/os.h
+++ b/include/spdlog/details/os.h
@@ -12,8 +12,9 @@
 #include <string>
 #include <chrono>
 #include <thread>
-#include <stdio.h>
-#include <string.h>
+#include <algorithm>
+#include <cstring>
+#include <cstdlib>
 #include <sys/stat.h>
 #include <sys/types.h>
 
@@ -364,6 +365,22 @@ inline std::string filename_to_str(const filename_t& filename)
 }
 #endif
 
+inline std::string errno_to_string(char [256], char* res)
+{
+    return std::string(res);
+}
+
+inline std::string errno_to_string(char buf[256], int res)
+{
+    if (res == 0)
+    {
+        return std::string(buf);
+    }
+    else
+    {
+        return "Unknown error";
+    }
+}
 
 // Return errno string (thread safe)
 inline std::string errno_str(int err_num)
@@ -375,7 +392,7 @@ inline std::string errno_str(int err_num)
     if(strerror_s(buf, buf_size, err_num) == 0)
         return std::string(buf);
     else
-        return "Unkown error";
+        return "Unknown error";
 
 #elif defined(__FreeBSD__) || defined(__APPLE__) || defined(ANDROID) || defined(__SUNPRO_CC) || \
       ((_POSIX_C_SOURCE >= 200112L) && ! defined(_GNU_SOURCE)) // posix version
@@ -383,10 +400,11 @@ inline std::string errno_str(int err_num)
     if (strerror_r(err_num, buf, buf_size) == 0)
         return std::string(buf);
     else
-        return "Unkown error";
+        return "Unknown error";
 
 #else  // gnu version (might not use the given buf, so its retval pointer must be used)
-    return std::string(strerror_r(err_num, buf, buf_size));
+    auto err = strerror_r(err_num, buf, buf_size); // let compiler choose type
+    return errno_to_string(buf, err); // use overloading to select correct stringify function
 #endif
 }
 
@@ -401,6 +419,36 @@ inline int pid()
 
 }
 
+
+// Detrmine if the terminal supports colors
+// Source: https://github.com/agauniyal/rang/
+inline bool is_color_terminal()
+{
+#ifdef _WIN32
+    return true;
+#else
+    static constexpr const char* Terms[] =
+    {
+        "ansi", "color", "console", "cygwin", "gnome", "konsole", "kterm",
+        "linux", "msys", "putty", "rxvt", "screen", "vt100", "xterm"
+    };
+
+    const char *env_p = std::getenv("TERM");
+    if (env_p == nullptr)
+    {
+        return false;
+    }
+
+    static const bool result = std::any_of(
+                                   std::begin(Terms), std::end(Terms), [&](const char* term)
+    {
+        return std::strstr(env_p, term) != nullptr;
+    });
+    return result;
+#endif
+}
+
+
 } //os
 } //details
 } //spdlog
diff --git a/include/spdlog/details/pattern_formatter_impl.h b/include/spdlog/details/pattern_formatter_impl.h
index 70b9dc80..5d47a04e 100644
--- a/include/spdlog/details/pattern_formatter_impl.h
+++ b/include/spdlog/details/pattern_formatter_impl.h
@@ -99,7 +99,7 @@ static const days_array& full_days()
     static const days_array arr{ { "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday" } };
     return arr;
 }
-class A_formatter:public flag_formatter
+class A_formatter SPDLOG_FINAL :public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -128,7 +128,7 @@ static const months_array& full_months()
     static const months_array arr{ { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" } };
     return arr;
 }
-class B_formatter:public flag_formatter
+class B_formatter SPDLOG_FINAL :public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -153,7 +153,7 @@ static fmt::MemoryWriter& pad_n_join(fmt::MemoryWriter& w, int v1, int v2, int v
 
 
 //Date and time representation (Thu Aug 23 15:35:46 2014)
-class c_formatter:public flag_formatter
+class c_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -164,7 +164,7 @@ class c_formatter:public flag_formatter
 
 
 // year - 2 digit
-class C_formatter:public flag_formatter
+class C_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -175,7 +175,7 @@ class C_formatter:public flag_formatter
 
 
 // Short MM/DD/YY date, equivalent to %m/%d/%y 08/23/01
-class D_formatter:public flag_formatter
+class D_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -185,7 +185,7 @@ class D_formatter:public flag_formatter
 
 
 // year - 4 digit
-class Y_formatter:public flag_formatter
+class Y_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -194,7 +194,7 @@ class Y_formatter:public flag_formatter
 };
 
 // month 1-12
-class m_formatter:public flag_formatter
+class m_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -203,7 +203,7 @@ class m_formatter:public flag_formatter
 };
 
 // day of month 1-31
-class d_formatter:public flag_formatter
+class d_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -212,7 +212,7 @@ class d_formatter:public flag_formatter
 };
 
 // hours in 24 format  0-23
-class H_formatter:public flag_formatter
+class H_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -221,7 +221,7 @@ class H_formatter:public flag_formatter
 };
 
 // hours in 12 format  1-12
-class I_formatter:public flag_formatter
+class I_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -230,7 +230,7 @@ class I_formatter:public flag_formatter
 };
 
 // minutes 0-59
-class M_formatter:public flag_formatter
+class M_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -239,7 +239,7 @@ class M_formatter:public flag_formatter
 };
 
 // seconds 0-59
-class S_formatter:public flag_formatter
+class S_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -248,7 +248,7 @@ class S_formatter:public flag_formatter
 };
 
 // milliseconds
-class e_formatter:public flag_formatter
+class e_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm&) override
     {
@@ -259,7 +259,7 @@ class e_formatter:public flag_formatter
 };
 
 // microseconds
-class f_formatter:public flag_formatter
+class f_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm&) override
     {
@@ -270,7 +270,7 @@ class f_formatter:public flag_formatter
 };
 
 // nanoseconds
-class F_formatter:public flag_formatter
+class F_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm&) override
     {
@@ -281,7 +281,7 @@ class F_formatter:public flag_formatter
 };
 
 // AM/PM
-class p_formatter:public flag_formatter
+class p_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -291,7 +291,7 @@ class p_formatter:public flag_formatter
 
 
 // 12 hour clock 02:55:02 pm
-class r_formatter:public flag_formatter
+class r_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -300,7 +300,7 @@ class r_formatter:public flag_formatter
 };
 
 // 24-hour HH:MM time, equivalent to %H:%M
-class R_formatter:public flag_formatter
+class R_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -309,7 +309,7 @@ class R_formatter:public flag_formatter
 };
 
 // ISO 8601 time format (HH:MM:SS), equivalent to %H:%M:%S
-class T_formatter:public flag_formatter
+class T_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -319,12 +319,12 @@ class T_formatter:public flag_formatter
 
 
 // ISO 8601 offset from UTC in timezone (+-HH:MM)
-class z_formatter:public flag_formatter
+class z_formatter SPDLOG_FINAL:public flag_formatter
 {
 public:
     const std::chrono::seconds cache_refresh = std::chrono::seconds(5);
 
-    z_formatter():_last_update(std::chrono::seconds(0))
+    z_formatter():_last_update(std::chrono::seconds(0)), _offset_minutes(0)
     {}
     z_formatter(const z_formatter&) = delete;
     z_formatter& operator=(const z_formatter&) = delete;
@@ -376,7 +376,7 @@ private:
 
 
 // Thread id
-class t_formatter:public flag_formatter
+class t_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm&) override
     {
@@ -385,7 +385,7 @@ class t_formatter:public flag_formatter
 };
 
 // Current pid
-class pid_formatter:public flag_formatter
+class pid_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm&) override
     {
@@ -394,7 +394,7 @@ class pid_formatter:public flag_formatter
 };
 
 
-class v_formatter:public flag_formatter
+class v_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm&) override
     {
@@ -402,7 +402,7 @@ class v_formatter:public flag_formatter
     }
 };
 
-class ch_formatter:public flag_formatter
+class ch_formatter SPDLOG_FINAL:public flag_formatter
 {
 public:
     explicit ch_formatter(char ch): _ch(ch)
@@ -417,7 +417,7 @@ private:
 
 
 //aggregate user chars to display as is
-class aggregate_formatter:public flag_formatter
+class aggregate_formatter SPDLOG_FINAL:public flag_formatter
 {
 public:
     aggregate_formatter()
@@ -436,7 +436,7 @@ private:
 
 // Full info formatter
 // pattern: [%Y-%m-%d %H:%M:%S.%e] [%n] [%l] %v
-class full_formatter:public flag_formatter
+class full_formatter SPDLOG_FINAL:public flag_formatter
 {
     void format(details::log_msg& msg, const std::tm& tm_time) override
     {
@@ -645,7 +645,7 @@ inline void spdlog::pattern_formatter::handle_flag(char flag)
         _formatters.push_back(std::unique_ptr<details::flag_formatter>(new details::pid_formatter()));
         break;
 
-    default: //Unkown flag appears as is
+    default: //Unknown flag appears as is
         _formatters.push_back(std::unique_ptr<details::flag_formatter>(new details::ch_formatter('%')));
         _formatters.push_back(std::unique_ptr<details::flag_formatter>(new details::ch_formatter(flag)));
         break;
diff --git a/include/spdlog/formatter.h b/include/spdlog/formatter.h
index 0ffcec03..639cc7d2 100644
--- a/include/spdlog/formatter.h
+++ b/include/spdlog/formatter.h
@@ -25,7 +25,7 @@ public:
     virtual void format(details::log_msg& msg) = 0;
 };
 
-class pattern_formatter : public formatter
+class pattern_formatter SPDLOG_FINAL : public formatter
 {
 
 public:
diff --git a/include/spdlog/logger.h b/include/spdlog/logger.h
index 58b4841a..af6f93fd 100644
--- a/include/spdlog/logger.h
+++ b/include/spdlog/logger.h
@@ -43,6 +43,16 @@ public:
     template <typename Arg1, typename... Args> void warn(const char* fmt, const Arg1&, const Args&... args);
     template <typename Arg1, typename... Args> void error(const char* fmt, const Arg1&, const Args&... args);
     template <typename Arg1, typename... Args> void critical(const char* fmt, const Arg1&, const Args&... args);
+#ifdef SPDLOG_WCHAR_TO_UTF8_SUPPORT
+    template <typename... Args> void log(level::level_enum lvl, const wchar_t* msg);
+    template <typename... Args> void log(level::level_enum lvl, const wchar_t* fmt, const Args&... args);
+    template <typename... Args> void trace(const wchar_t* fmt, const Args&... args);
+    template <typename... Args> void debug(const wchar_t* fmt, const Args&... args);
+    template <typename... Args> void info(const wchar_t* fmt, const Args&... args);
+    template <typename... Args> void warn(const wchar_t* fmt, const Args&... args);
+    template <typename... Args> void error(const wchar_t* fmt, const Args&... args);
+    template <typename... Args> void critical(const wchar_t* fmt, const Args&... args);
+#endif // SPDLOG_WCHAR_TO_UTF8_SUPPORT
 
     template <typename T> void log(level::level_enum lvl, const T&);
     template <typename T> void trace(const T&);
diff --git a/include/spdlog/sinks/android_sink.h b/include/spdlog/sinks/android_sink.h
index d8c97e03..be2d3ad8 100644
--- a/include/spdlog/sinks/android_sink.h
+++ b/include/spdlog/sinks/android_sink.h
@@ -12,6 +12,12 @@
 #include <mutex>
 #include <string>
 #include <android/log.h>
+#include <thread>
+#include <chrono>
+
+#if !defined(SPDLOG_ANDROID_RETRIES)
+#define SPDLOG_ANDROID_RETRIES 2
+#endif
 
 namespace spdlog
 {
@@ -25,15 +31,23 @@ namespace sinks
 class android_sink : public sink
 {
 public:
-    explicit android_sink(const std::string& tag = "spdlog"): _tag(tag) {}
+    explicit android_sink(const std::string& tag = "spdlog", bool use_raw_msg = false): _tag(tag), _use_raw_msg(use_raw_msg) {}
 
     void log(const details::log_msg& msg) override
     {
         const android_LogPriority priority = convert_to_android(msg.level);
+        const char *msg_output = (_use_raw_msg ? msg.raw.c_str() : msg.formatted.c_str());
+
         // See system/core/liblog/logger_write.c for explanation of return value
-        const int ret = __android_log_write(
-                            priority, _tag.c_str(), msg.formatted.c_str()
-                        );
+        int ret = __android_log_write(priority, _tag.c_str(), msg_output);
+        int retry_count = 0;
+        while ((ret == -11/*EAGAIN*/) && (retry_count < SPDLOG_ANDROID_RETRIES))
+        {
+            std::this_thread::sleep_for(std::chrono::milliseconds(5));
+            ret = __android_log_write(priority, _tag.c_str(), msg_output);
+            retry_count++;
+        }
+
         if (ret < 0)
         {
             throw spdlog_ex("__android_log_write() failed", ret);
@@ -67,6 +81,7 @@ private:
     }
 
     std::string _tag;
+    bool _use_raw_msg;
 };
 
 }
diff --git a/include/spdlog/sinks/ansicolor_sink.h b/include/spdlog/sinks/ansicolor_sink.h
index 96e10148..0e5e53c6 100644
--- a/include/spdlog/sinks/ansicolor_sink.h
+++ b/include/spdlog/sinks/ansicolor_sink.h
@@ -7,6 +7,7 @@
 
 #include <spdlog/sinks/base_sink.h>
 #include <spdlog/common.h>
+#include <spdlog/details/os.h>
 
 #include <string>
 #include <map>
@@ -21,7 +22,7 @@ namespace sinks
  * the output with an ANSI escape sequence color code depending on the severity
  * of the message.
  */
-class ansicolor_sink : public sink
+class ansicolor_sink SPDLOG_FINAL: public sink
 {
 public:
     ansicolor_sink(sink_ptr wrapped_sink);
@@ -36,64 +37,74 @@ public:
     void set_color(level::level_enum color_level, const std::string& color);
 
     /// Formatting codes
-    const std::string reset      = "\033[00m";
-    const std::string bold       = "\033[1m";
-    const std::string dark       = "\033[2m";
-    const std::string underline  = "\033[4m";
-    const std::string blink      = "\033[5m";
-    const std::string reverse    = "\033[7m";
-    const std::string concealed  = "\033[8m";
+    const std::string reset = "\033[00m";
+    const std::string bold = "\033[1m";
+    const std::string dark = "\033[2m";
+    const std::string underline = "\033[4m";
+    const std::string blink = "\033[5m";
+    const std::string reverse = "\033[7m";
+    const std::string concealed = "\033[8m";
 
     // Foreground colors
-    const std::string grey       = "\033[30m";
-    const std::string red        = "\033[31m";
-    const std::string green      = "\033[32m";
-    const std::string yellow     = "\033[33m";
-    const std::string blue       = "\033[34m";
-    const std::string magenta    = "\033[35m";
-    const std::string cyan       = "\033[36m";
-    const std::string white      = "\033[37m";
+    const std::string grey = "\033[30m";
+    const std::string red = "\033[31m";
+    const std::string green = "\033[32m";
+    const std::string yellow = "\033[33m";
+    const std::string blue = "\033[34m";
+    const std::string magenta = "\033[35m";
+    const std::string cyan = "\033[36m";
+    const std::string white = "\033[37m";
 
     /// Background colors
-    const std::string on_grey    = "\033[40m";
-    const std::string on_red     = "\033[41m";
-    const std::string on_green   = "\033[42m";
-    const std::string on_yellow  = "\033[43m";
-    const std::string on_blue    = "\033[44m";
+    const std::string on_grey = "\033[40m";
+    const std::string on_red = "\033[41m";
+    const std::string on_green = "\033[42m";
+    const std::string on_yellow = "\033[43m";
+    const std::string on_blue = "\033[44m";
     const std::string on_magenta = "\033[45m";
-    const std::string on_cyan    = "\033[46m";
-    const std::string on_white   = "\033[47m";
+    const std::string on_cyan = "\033[46m";
+    const std::string on_white = "\033[47m";
 
 
 protected:
+    bool is_color_terminal_;
     sink_ptr sink_;
     std::map<level::level_enum, std::string> colors_;
 };
 
-inline ansicolor_sink::ansicolor_sink(sink_ptr wrapped_sink) : sink_(wrapped_sink)
+inline ansicolor_sink::ansicolor_sink(sink_ptr wrapped_sink): sink_(wrapped_sink)
 {
-    colors_[level::trace]   = cyan;
-    colors_[level::debug]   = cyan;
-    colors_[level::info]    = bold;
-    colors_[level::warn]    = yellow + bold;
-    colors_[level::err]     = red + bold;
+    is_color_terminal_ = details::os::is_color_terminal();
+    colors_[level::trace] = cyan;
+    colors_[level::debug] = cyan;
+    colors_[level::info] = bold;
+    colors_[level::warn] = yellow + bold;
+    colors_[level::err] = red + bold;
     colors_[level::critical] = bold + on_red;
-    colors_[level::off]      = reset;
+    colors_[level::off] = reset;
 }
 
 inline void ansicolor_sink::log(const details::log_msg& msg)
 {
-    // Wrap the originally formatted message in color codes
-    const std::string& prefix = colors_[msg.level];
-    const std::string& s = msg.formatted.str();
-    const std::string& suffix = reset;
-    details::log_msg m;
-    m.level = msg.level;
-    m.logger_name = msg.logger_name;
-    m.time = msg.time;
-    m.thread_id = msg.thread_id;
-    m.formatted << prefix  << s << suffix;
-    sink_->log(m);
+    // Wrap the originally formatted message in color codes.
+    // If color is not supported in the terminal, log as is instead.
+    if (is_color_terminal_)
+    {
+        const std::string& prefix = colors_[msg.level];
+        const std::string& s = msg.formatted.str();
+        const std::string& suffix = reset;
+        details::log_msg m;
+        m.level = msg.level;
+        m.logger_name = msg.logger_name;
+        m.time = msg.time;
+        m.thread_id = msg.thread_id;
+        m.formatted << prefix << s << suffix;
+        sink_->log(m);
+    }
+    else
+    {
+        sink_->log(msg);
+    }
 }
 
 inline void ansicolor_sink::flush()
diff --git a/include/spdlog/sinks/base_sink.h b/include/spdlog/sinks/base_sink.h
index 7f1a31db..c0a910e0 100644
--- a/include/spdlog/sinks/base_sink.h
+++ b/include/spdlog/sinks/base_sink.h
@@ -5,8 +5,8 @@
 
 #pragma once
 //
-// base sink templated over a mutex (either dummy or realy)
-// concrete implementation should only overrid the _sink_it method.
+// base sink templated over a mutex (either dummy or real)
+// concrete implementation should only override the _sink_it method.
 // all locking is taken care of here so no locking needed by the implementers..
 //
 
@@ -31,7 +31,7 @@ public:
     base_sink(const base_sink&) = delete;
     base_sink& operator=(const base_sink&) = delete;
 
-    void log(const details::log_msg& msg) override
+    void log(const details::log_msg& msg) SPDLOG_FINAL override
     {
         std::lock_guard<Mutex> lock(_mutex);
         _sink_it(msg);
diff --git a/include/spdlog/sinks/file_sinks.h b/include/spdlog/sinks/file_sinks.h
index 721a96df..fe40a362 100644
--- a/include/spdlog/sinks/file_sinks.h
+++ b/include/spdlog/sinks/file_sinks.h
@@ -26,7 +26,7 @@ namespace sinks
  * Trivial file sink with single file as target
  */
 template<class Mutex>
-class simple_file_sink : public base_sink < Mutex >
+class simple_file_sink SPDLOG_FINAL : public base_sink < Mutex >
 {
 public:
     explicit simple_file_sink(const filename_t &filename, bool truncate = false):_force_flush(false)
@@ -61,7 +61,7 @@ typedef simple_file_sink<details::null_mutex> simple_file_sink_st;
  * Rotating file sink based on size
  */
 template<class Mutex>
-class rotating_file_sink : public base_sink < Mutex >
+class rotating_file_sink SPDLOG_FINAL : public base_sink < Mutex >
 {
 public:
     rotating_file_sink(const filename_t &base_filename,
@@ -177,7 +177,7 @@ struct dateonly_daily_file_name_calculator
  * Rotating file sink based on date. rotates at midnight
  */
 template<class Mutex, class FileNameCalc = default_daily_file_name_calculator>
-class daily_file_sink :public base_sink < Mutex >
+class daily_file_sink SPDLOG_FINAL :public base_sink < Mutex >
 {
 public:
     //create daily file sink which rotates on given time
diff --git a/include/spdlog/sinks/stdout_sinks.h b/include/spdlog/sinks/stdout_sinks.h
index c05f80dd..4dd52ed8 100644
--- a/include/spdlog/sinks/stdout_sinks.h
+++ b/include/spdlog/sinks/stdout_sinks.h
@@ -18,7 +18,7 @@ namespace sinks
 {
 
 template <class Mutex>
-class stdout_sink: public base_sink<Mutex>
+class stdout_sink SPDLOG_FINAL : public base_sink<Mutex>
 {
     using MyType = stdout_sink<Mutex>;
 public:
@@ -47,7 +47,7 @@ typedef stdout_sink<std::mutex> stdout_sink_mt;
 
 
 template <class Mutex>
-class stderr_sink: public base_sink<Mutex>
+class stderr_sink SPDLOG_FINAL : public base_sink<Mutex>
 {
     using MyType = stderr_sink<Mutex>;
 public:
diff --git a/include/spdlog/tweakme.h b/include/spdlog/tweakme.h
index 86f66b9e..c167c716 100644
--- a/include/spdlog/tweakme.h
+++ b/include/spdlog/tweakme.h
@@ -101,8 +101,22 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to enable wchar_t support (convert to utf8)
+//
+// #define SPDLOG_WCHAR_TO_UTF8_SUPPORT
+///////////////////////////////////////////////////////////////////////////////
+
 ///////////////////////////////////////////////////////////////////////////////
 // Uncomment to prevent child processes from inheriting log file descriptors
 //
 // #define SPDLOG_PREVENT_CHILD_FD
 ///////////////////////////////////////////////////////////////////////////////
+
+///////////////////////////////////////////////////////////////////////////////
+// Uncomment to mark some types as final, allowing more optimizations in release
+// mode with recent compilers. See GCC's documentation for -Wsuggest-final-types
+// for instance.
+//
+// #define SPDLOG_FINAL final
+///////////////////////////////////////////////////////////////////////////////
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index ce275ccb..22329b4e 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -10,7 +10,7 @@ find_package(Threads)
 add_library(catch INTERFACE)
 target_include_directories(catch INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})
 
-file(GLOB catch_tests LIST_DIRECTORIES false RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} *.cpp)
+file(GLOB catch_tests LIST_DIRECTORIES false RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} *.cpp *.h *.hpp)
 
 add_executable(catch_tests ${catch_tests})
 target_link_libraries(catch_tests spdlog ${CMAKE_THREAD_LIBS_INIT})