How can I make the contents of an #include-file a compile-time constant in a cpp-file?
c++, compiler-construction, self-modifying, syntax
Solution
The only real solution I know is to write a small program which converts a file into a C++ definition of a string variable containing it. This is fairly simple to write: output a simple header along the lines of:
char const variableName[] =
Then copy each line of the file, wrapping it in `"...\n"`, and escaping any characters necessary. (If you can be sure of C++11, then you might be able to do something with `R"..."`, but I've no experience with this.)
[update: refering to the original question with a typo in it]: Your solution should not work; if it does, it is an error in the compiler. According to §2.2, tokenization occurs before the execution of preprocessing directives. So when the execution of preprocessing directives occurs, you have a string literal, and not a `#` preprocessing token. (Compiler errors are to be expected when using C++11 features. There's not been enough time yet for the implementers to get all of the bugs out.)
Problem
I have a file `module.hpp` ``` struct ModuleBase { virtual void run() = 0; }; ``` and a `main.cpp` program ``` int main() { cout << ...?...; // here should go the contents of module.hpp } ``` What can I put at `...?...` to let the contents of the header file printed here? A basic idea would be ``` int main() { static const string content = R"( #include <module.hpp> )"; cout << content; } ``` but multi-line-strings are only available in C++11, and `#include` does not work inside multi-line strings (which is good)? If there is a non-portable way for the gcc... that would be a start. Clarification (update): The substitution should be done at compile time.