What's #pragma comment (lib, "lib/glut32.lib")?

Question

I saw the code on the top of a GLUT demo and I'm curious about its functionality.

Why would someone want to write a #pragma instead of just including the library?

Answer 1

This pragma allows the library author to define library imports based on a range of criteria that can be analysed at compile-time. For instance, you can link against different libs, based on whether you want to link with:

• multithreading on or off;
• the shared or static version of the library in question;
• the shared or static version of the standard runtime library;
• the debug or release library;
• the 32-bit or 64-bit library.

With the pragma form, all this can be decided via #ifdef preprocessor tests in one of the library's header files.