Why it is good practice to define custom datatypes in larger projects

Question

Please help me understand reason of defining C types in some projects.

In my current company I found that someone made definitions of types that are equivalent of those that are already defined in <stdint.h>.

Such approach makes harder to integrate 3party code into project, and makes programmer work, bit more frustrating.

But I can also see that some projects, like gnome do the same. There is a gchar, gsize, and gint32 for example.

Because I don't see ANY reason for such approach, I kindly ask for explanation.

What is the reason that <stdint.h> isn't sufficient.

Go back to Windows types UINT, WORD, BYTE etc. There was no certain standard at that time. — Michael Chourdakis, Jun 26 '19 at 19:35
Although not mandatory, `typedef` is helpful if you want to make an enumerated type or function pointer type to make your code easier to read/maintain. — Jim Fell, Jun 26 '19 at 20:22

score 4 · Accepted Answer · answered Jun 26 '19 at 19:34

4

This is not good practice. It only leads to less compatibility and portability. I don't see any reason that it should be done. stdint.h exists to avoid this.

answered Jun 26 '19 at 19:34

Thomas Jager

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But it didn't always. – Dave Newton Jun 26 '19 at 19:40

John Kugelman · Answer 2 · 2019-06-26T19:43:25.443

<stdint.h> was standardized in C99. Perhaps the codebase predates <stdint.h>, or it needs to compile on platforms that don't have it. It was an extremely common thing to do in C89 and K&R C when there were no portable fixed size typedefs. Even modern projects may keep around these compatibility shims if they still aim to be compilable on decades-old platforms.

In my current company I found that someone made definitions of types that are equivalent of those that are already defined in <stdint.h>.

If your codebase targets C99 or later then there's no need.

Why it is good practice to define custom datatypes in larger projects

2 Answers2