-/// Version number. If Version is left empty, then compile date, in the
-/// format DD-MM-YY, is shown in engine_info.
-static const string Version = "";
+namespace {
+
+/// Version number. If Version is left empty, then compile date in the format
+/// DD-MM-YY and show in engine_info.
+const string Version = "";
+
+/// Our fancy logging facility. The trick here is to replace cin.rdbuf() and
+/// cout.rdbuf() with two Tie objects that tie cin and cout to a file stream. We
+/// can toggle the logging of std::cout and std:cin at runtime whilst preserving
+/// usual I/O functionality, all without changing a single line of code!
+/// Idea from http://groups.google.com/group/comp.lang.c++/msg/1d941c0f26ea0d81
+
+struct Tie: public streambuf { // MSVC requires split streambuf for cin and cout
+
+ Tie(streambuf* b, streambuf* l) : buf(b), logBuf(l) {}
+
+ int sync() override { return logBuf->pubsync(), buf->pubsync(); }
+ int overflow(int c) override { return log(buf->sputc((char)c), "<< "); }
+ int underflow() override { return buf->sgetc(); }
+ int uflow() override { return log(buf->sbumpc(), ">> "); }