Allow use after static destruction took place

.gitignore

@@ -1 +1,2 @@
 build/
+.vscode

logger/Logger.cxx

@@ -13,6 +13,7 @@
 #include <chrono>
 #include <ctime> // strftime
 #include <iomanip> // setw, setfill
+#include <cstdio> // printf
 
 using namespace std;
 
@@ -84,6 +85,8 @@ Severity Logger::fMinSeverity = Severity::info;
 function<void()> Logger::fFatalCallback;
 unordered_map<string, pair<Severity, function<void(const string& content, const LogMetaData& metadata)>>> Logger::fCustomSinks;
 mutex Logger::fMtx;
+bool Logger::fIsDestructed = false;
+Logger::DestructionHelper fDestructionHelper;
 
 #if defined(__APPLE__) || defined(__FreeBSD__)
 const string Logger::fProcessName = getprogname();
@@ -199,6 +202,7 @@ string Logger::VerbosityName(Verbosity verbosity)
 
 Logger::Logger(Severity severity, const string& file, const string& line, const string& func)
 {
+    if (!fIsDestructed) {
         chrono::time_point<chrono::system_clock> now = chrono::system_clock::now();
         size_t pos = file.rfind("/");
 
@@ -210,6 +214,7 @@ Logger::Logger(Severity severity, const string& file, const string& line, const
         fMetaData.func = func;
         fMetaData.severity_name = fSeverityNames.at(static_cast<size_t>(severity));
         fMetaData.severity = severity;
+    }
 }
 
 void Logger::SetConsoleSeverity(const Severity severity)
@@ -524,6 +529,10 @@ void Logger::RemoveCustomSink(const string& key)
 
 Logger& Logger::Log()
 {
+    if (fIsDestructed) {
+        return *this;
+    }
+
     char tsstr[32];
     {
         lock_guard<mutex> lock(fMtx); // localtime is not threadsafe, guard it
@@ -639,6 +648,11 @@ Logger& Logger::operator<<(ostream& (*manip) (ostream&))
 
 Logger::~Logger() noexcept(false)
 {
+    if (fIsDestructed) {
+        printf("post-static destruction output: %s\n", fContent.str().c_str());
+        return;
+    }
+
     for (auto& it : fCustomSinks) {
         if (LoggingCustom(it.second.first)) {
             lock_guard<mutex> lock(fMtx);

logger/Logger.h

@@ -335,6 +335,10 @@ class Logger
 
     virtual ~Logger() noexcept(false);
 
+    // protection for use after static destruction took place
+    static bool fIsDestructed;
+    static struct DestructionHelper { ~DestructionHelper() { Logger::fIsDestructed = true; }} fDestructionHelper;
+
   private:
     LogMetaData fMetaData;