Pragmas

A pragma statement is a directive for the compiler to perform a specific task at compile time. In C and C++, it's a preprocessor directive, but in D it's an actual statement. At the time of writing, there are five predefined pragmas. We'll go through three of them here; the other two are for more advanced usage. The language also allows for vendor-specific pragmas. When a compiler encounters one that it doesn't recognize, such as one from a different compiler vendor, it is required to emit an error. Vendor-specific pragmas can be used by versioning them, something you'll learn how to do in the next section. For more on pragmas, refer to http://dlang.org/pragma.html.

The lib pragma

The lib pragma is a way to instruct the compiler in code as to which libraries should be linked at compile time. Here's an example.

pragma(lib, "OpenGL32.lib");

This will cause the compiler to insert a directive into the object file that the linker can then use to link...