When I write software in C, should I put static and inline functions in the .h or in the .c file?
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syntagma
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3Their declaration or definition ? – VAndrei Apr 25 '15 at 17:06
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2You should not put `static` functions in a `.h` file, because if you need to, then the function should not be static. – Iharob Al Asimi Apr 25 '15 at 17:08
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Do not put the declaration nor definition of a static function (or variable) in a .h file. That defeats the points of static - keeping functions/variables local.
inline is another matter - it depends on the scope meant for the function. An inline function in a .h is meant for global usage and scope. An inline function in a .c is meant for local usage only. This is much the same strategy as would be used for a #define
inline functions can be extern, static or unspecified. @Christoph well explains inline scope issues.
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chux - Reinstate Monica
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True, except you usually want your inline functions static. At least I rarely bother to instantiate external inline definitions. – doynax Apr 25 '15 at 20:59
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1A good read about the why and how of inline and static functions in C, is [**Inline Functions In C**](http://www.greenend.org.uk/rjk/tech/inline.html) – David C. Rankin Apr 26 '15 at 01:21
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Assuming multiple C source files include the .h file, then inline functions in the .h file are ok, but I'm not sure why you'd want a static function in a .h file, to end up being duplicated, once for each C source file. The compiler may be smart enough to not generate code for static functions that are not called within a C source file.
rcgldr
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