Logging Macros STXXL_MSG

All STXXL components should output log or trace messages using the following macros. There are two basic methods for logging using ostream syntax:

// for plain messages
STXXL_MSG("text " << var)
// for error messages
STXXL_ERRMSG("error message " << reason)

For debugging and tracing the following macros can be used for increasing levels of verbosity:

// level 0 (for current debugging)
STXXL_VERBOSE0("text " << var)
// level 1,2 and 3 for more verbose debugging level
STXXL_VERBOSE1("text " << var)
STXXL_VERBOSE2("text " << var)
STXXL_VERBOSE3("text " << var)

A method used by some submodule authors to create their own levels of verbosity is to make their own debugging macros:

#define STXXL_VERBOSE_VECTOR(msg) STXXL_VERBOSE1("vector[" << static_cast<const void *>(this) << "]::" << msg)