added example

example/multisink.cpp

@@ -0,0 +1,47 @@
+#include "spdlog/spdlog.h"
+
+#include <iostream>
+#include <memory>
+
+namespace spd = spdlog;
+int main(int, char*[])
+{
+    bool enable_debug = true;
+    try
+    {
+        // This other example use a single logger with multiple sinks.
+        // This means that the same log_msg is forwarded to multiple sinks;
+        // Each sink can have it's own log level and a message will be logged.
+        std::vector<spdlog::sink_ptr> sinks;
+        sinks.push_back( std::make_shared<spdlog::sinks::stdout_sink_mt>() );
+        sinks.push_back( std::make_shared<spdlog::sinks::simple_file_sink_mt>("./log_regular_file.txt") );
+        sinks.push_back( std::make_shared<spdlog::sinks::simple_file_sink_mt>("./log_debug_file.txt") );
+
+        spdlog::logger console_multisink("multisink",  sinks.begin(), sinks.end() );
+        console_multisink.set_level( spdlog::level::warn);
+
+        sinks[0]->set_level( spdlog::level::trace);  // console. Allow everything.  Default value
+        sinks[1]->set_level( spdlog::level::trace);  //  regular file. Allow everything.  Default value
+        sinks[2]->set_level( spdlog::level::off);    //  regular file. Ignore everything.
+
+        console_multisink.warn("warn: will print only on console and regular file");
+
+        if( enable_debug )
+        {
+            console_multisink.set_level( spdlog::level::debug); // level of the logger
+            sinks[1]->set_level( spdlog::level::debug);  // regular file
+            sinks[2]->set_level( spdlog::level::debug);  // debug file
+        }
+        console_multisink.debug("Debug: you should see this on console and both files");
+
+        // Release and close all loggers
+        spdlog::drop_all();
+    }
+    // Exceptions will only be thrown upon failed logger or sink construction (not during logging)
+    catch (const spd::spdlog_ex& ex)
+    {
+        std::cout << "Log init failed: " << ex.what() << std::endl;
+        return 1;
+    }
+}
+