Can the C preprocessor be used to tell if a file exists?

by

Little Update

Some compilers might support __has_include ( header-name ).

The extension was added to the C++17 standard (P0061R1).

Compiler Support

  • Clang
  • GCC from 5.X
  • Visual Studio from VS2015 Update 2 (?)

Example (from clang website):

// Note the two possible file name string formats.
#if __has_include("myinclude.h") && __has_include(<stdint.h>)
# include "myinclude.h"
#endif

Sources

More Related Contents:

  1. What is the difference between #include and #include “filename”?
  2. C/C++, can you #include a file into a string literal? [duplicate]
  3. When can you omit the file extension in an #include directive?
  4. Include all files in a directory?
  5. Is the backslash acceptable in C and C++ #include directives?
  6. Using includes with c++ shared libraries
  7. C++ preprocessor __VA_ARGS__ number of arguments
  8. “#include” a text file in a C program as a char[]
  9. Can we have recursive macros?
  10. Including one C source file in another?
  11. Should I include or in C++ programs?
  12. How to identify platform/compiler from preprocessor macros?
  13. C++ Header order [closed]
  14. C/C++ macro/template blackmagic to generate unique name
  15. How to define several include path in Makefile
  16. Difference between using #include and #include in C++
  17. Difference between Enum and Define Statements
  18. macro definition containing #include directive
  19. What does “#define STR(a) #a” do?
  20. “No newline at end of file” compiler warning
  21. How does #include work in C++?
  22. Header file included only once in entire program?
  23. Confused by squaring macro SQR in c [duplicate]
  24. C++ #include semantics
  25. Generate include file name in a macro
  26. Function already defined error in C++
  27. How do I temporarily disable a macro expansion in C/C++?
  28. How can I see the output of the Visual C++ preprocessor? [duplicate]
  29. Do you know tool building tree of include files in project\file?
  30. #ifdef vs #if – which is better/safer as a method for enabling/disabling compilation of particular sections of code?

Leave a Comment