The three-step program

There are essentially three steps to using a library within your Rust application:

1. Including the dependency.
2. Writing code that uses the library.
3. Building your application to link to the library.

The most difficult stage is the second as it requires writing code, call back code, and other such wrappers to use the library.

Including the dependency

As with using any library not provided by Prelude, the compiler has to know of the existence of the library. As we did in Chapter 8, The Rust Application Lifetime, we let the compiler know to expect an external library by including in the Cargo.toml file, as follows:

[dependency] 
libc = "0.2.0" 

The figure in quotes is the library version. This is...