Preformatted code starts with a space or a tab. The code will be syntax highlighted according to the current Source Mode:

#include <iostream>

int main()
{
    // Sample code
    std::cout << "Hello, World\n";
    return 0;
}

import cgi

def cookForHtml(text):
    '''"Cooks" the input text for HTML.'''

    return cgi.escape(text)

Macros that are already defined are expanded in source code. Example:

[def __array__ [@http://www.boost.org/doc/html/array/reference.html array]]
[def __boost__ [@http://www.boost.org/libs/libraries.htm boost]]

    using __boost__::__array__;

Generates:

using boost::array;

In quickbook 1.7 and later, you can include callouts in code blocks, like so:

[!c++]
    std::string foo_bar() /*< The /Mythical/ FooBar.
                          See [@http://en.wikipedia.org/wiki/Foobar Foobar for details] >*/
    {
        return "foo-bar"; /*< return 'em, foo-bar man! >*/
    }

Which will generate:

std::string foo_bar() 
{
    return "foo-bar"; 
}