Editing C preprocessor (section)

=== C/C++ ===
The following tokens are recognised by the preprocessor in the context of preprocessor directives.
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* <code>#if</code>
* <code>#elif</code>
* <code>#else</code>
* <code>#endif</code>
* <code>#ifdef</code>
* <code>#ifndef</code>
* <code>#elifdef</code>
* <code>#elifndef</code>
* <code>#define</code>
* <code>#undef</code>
* <code>#include</code>
* <code>#embed</code>
* <code>#line</code>
* <code>#error</code>
* <code>#warning</code>
* <code>#pragma</code>
* <code>defined</code> (follows a conditional directive; not actually a directive, but rather an operator)
* <code>#__has_include</code>
* <code>#__has_cpp_attribute</code> (C++ only)
* <code>#__has_embed</code>
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Until [[C++26]], the C++ keywords <code>import</code>, <code>export</code>, and <code>module</code> were partially handled by the preprocessor as well.

Haskell also accepts C preprocessor directives.