外部标头包含在C ++中

Question

I have two projects, and they have some headers in common, so they both include those headers. Now my question is: Can I implement these headers in outside cpp files. For example when the header is inside the project you just declare the functions and implement them in .cpp file, and because the .cpp file is in the project the compiler will know where to get these functions implementation.

So how do I do the same for outside headers?? include both .h and .cpp?? implement all the functions inside the .h??

Thanks.

Answer 1

typically, you will create a dynamic or static library for the definitions found in the cpp files - these are the exported definitions of the declarations in the headers you share.

then you would link your app/executable to that library.

during linking, the linker will locate the symbols referenced by the app in the static/dynamic library you made. if you have implemented and configured everything correctly, there will be no linker errors.

Answer 2

It depends on what you are trying to accomplish. I valid solution is to create a "header only" file where the implementation is in the declaration. A large portion of the boost library does this.

Another option would be to put your common code in another project, and link to it.