c++ - #include anywhere

Question

Is the #include <file> meant to be used for headers only or is it simply a mechanical "inject this code here" that can be used anywhere in the code?

What if I use it in the middle of a cpp function to just "inject" code from a single source? will this work or will compilers scream about this?

Answer 1

It is a mechanical inject the code here device. You can include a text file containing Goethe's Faust if you wish to. You can put it anywhere, even in the middle of a function (of course, #include needs a fresh line!).

However, it's strong convention to only use #include for header files. There may be reasons where I wouldn't object on it, for example pulling in machine-generated code or merging all translation units in a single file.