Include multiple header-files at once with only one #include-expression?

问题

Is there any expression possible for the syntax to include multiple headers at once, with no need to write the "#include"-expression for each file new?

Like, for example:

#include <stdio.h>, <stdlib.h>, <curses.h>, <string.h>  /* Dummy-Expression 1. */

OR

#include <stdio.h> <stdlib.h> <curses.h> <string.h>     /* Dummy-Expression 2. */

Question is for C AND C++.

回答1:

No, there is no way to do this. You have to type out (or copy) each #include to its own line, like this:

#include <stdio.h>
#include <stdlib.h>
#include <curses.h>
#include <string.h>

This applies to both C and C++.

Some of the other answers discuss creating another header file that includes each of these, but I'm not going to discuss doing that. It in general is a bad idea and causes issues like namespace pollution and the need to recompile when you change that header file.

回答2:

No, there is not.

Write an #include directive for each inclusion operation you wish to perform.

You could, however, have a "utility" header that does nothing but include many other headers that you use frequently. Then you just include that one utility header. Whether this is a good idea or not, is a matter of opinion.

If you go down that route, don't be tempted to start relying on internal implementation headers.

回答3:

You can make a header file with all the common includes and include that in your files:

File common.h:

#include <stdio.h>
#include <stdlib.h>
#include <curses.h>
#include <string.h>

and in your file you can include that file instead:

#include <common.h>

回答4:

There's no syntax for that. But if you really want something like that, then just create a new header that contains nothing but multiple #include statements for the headers you want and then #include "combo-header.h" whenever needed. I'd discourage this though. Better to only include what you use explicitly where you use it - for several reasons; compile time and namespace pollution being the top ones.

回答5:

It can be done with a help of auxillary header including header:

#define HEADERS (<stdio.h>)(<stdlib.h>)(<curses.h>)(<string.h>)
#include "Headers.inl"

Where Headers.inl performs include for each item in HEADERS sequence:

// Headers.inl
#include <boost/preprocessor/seq.hpp>

#if(0 < BOOST_PP_SEQ_SIZE(HEADERS))
#include BOOST_PP_SEQ_ELEM(0, HEADERS)
#endif

#if(1 < BOOST_PP_SEQ_SIZE(HEADERS))
#include BOOST_PP_SEQ_ELEM(1, HEADERS)
#endif

#if(2 < BOOST_PP_SEQ_SIZE(HEADERS))
#include BOOST_PP_SEQ_ELEM(2, HEADERS)
#endif

#if(3 < BOOST_PP_SEQ_SIZE(HEADERS))
#include BOOST_PP_SEQ_ELEM(3, HEADERS)
#endif

…

It can probably be simplified by letting boost preprocessor handle the all the repetition with BOOST_PP_SEQ_POP_FRONT and recursive include of itself.

来源：https://stackoverflow.com/questions/58354443/include-multiple-header-files-at-once-with-only-one-include-expression

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c++

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include

header-files