Set the Runtime Library of the vc6.0 compilation Option

/Ml (default option) corresponds to the standard of the single-thread static versionProgramLibrary (libc. Lib );
/MT corresponds to the multi-threaded static version standard library (libcmt. Lib). At this time, the compiler automatically defines the _ Mt macro;
/MD corresponds to the multi-threaded dll version (imported to msvcrt. Lib, And the DLL is msvcrt. dll). The Compiler automatically defines two macros: _ MT and _ DLL.

The option D will allow the compiler to automatically define one more _ debug macro, indicating that the debugging version of the corresponding standard library is used. Therefore
/MLD corresponds to the single-thread static standard library (libcd. Lib) of the debug version ),
/MTD corresponds to the multi-thread static standard library (libcmtd. Lib) of the debug version ),
/MDD corresponds to the debugging version of the multi-threaded DLL standard library (imported into msvcrtd. Lib, DLL is msvcrtd. dll ).