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by inglor_cz 735 days ago
"Avoid #defines for constants like the plague. Use static constexpr instead."

Pretty much every C textbook I can think of now is full of #defines for constants. I, too, am (de)formed by this.
2 comments
sltkr 734 days ago
Because `constexpr` was not supported in C until very recently (C23).

And `static const` by itself is not a good alternative, because constants can't be used in a lot of places, for example when declaring the size of an array.

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nj5rq 734 days ago
Constants can be used for array sizes since a lot of C standards ago, right?
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PhilipRoman 734 days ago
They end up as a VLA which may or may not be what you want.
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niborgen 735 days ago
Thanks for your comment.

The blog post was written with C++ in mind, but I just learned that C now also has constexpr: https://en.cppreference.com/w/c/language/constexpr.

Time to update those books (:

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