Injecting code into methods based on UDA's

[TheFlyingFiddle]

void logMsg(string file, string msg)
{
  //Log the message to the file.
}

struct Log
{
   string logFile;
   LogInfo toLog;
}

class Foo
{
  void bar() { /* do something */ }
  @Log("fooInfo.txt", LogInfo.methodCall | LogInfo.returnValue)
void baz()
  {
    //Doess
  }
}