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Solving #109 with redundant inclusion guards #110

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jmramosr
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Using redundant include guards to minimize the compilation time

C Preprocessor inclusions could explode the compilation time (even with pragma once!)

The basic idea comes from an old, dusty C++ book called Large Scale C++ Software Design, page 83-88.

Expanding the evaluate method indicated in the issue #109, everytime the ? in 0?1?2?3?4?5?6?7?8?9? is parsed, a new template instantiation begins, reading all the files again in the #includes, and increasing exponentially the compilation time.

I didn't use any redundant include guards in the standard header files. They could be used into them, too, in order to reduce even more the compilation times.

Test case:
0?1?2?3?4?5?6?7?8?9?
Even worst compile time test case:
a?b?c?d?e?f?g?h?i?j?l?m?n?o?p?q?r?s?t?u?v?w?x?y?z?

To reduce compilation time explodes in ctre.hpp
  To reduce compilation time explodes
To reduce compilation time explodes
To reduce compilation time explodes
added CTRE_V2__CTLL__HPP redundant guard
To reduce compilation time explodes
To reduce compilation time explodes
To reduce compilation time explodes
To reduce compilation time explodes
To reduce compilation time explodes
To reduce compilation time explodes
To reduce compilation time explodes
To reduce compilation time explodes
To reduce compilation time explodes
To reduce compilation time explodes
To reduce compilation time explodes
@hanickadot
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Do you have some measurements? This seems really sketchy.

@hanickadot
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Ok, I read the book on pages you sent, the chapter is talking about preprocessor, not about templates.

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