Source files
SF.4
Include header files before other declarations in a file
Reason
Minimize context dependencies and increase readability.
Example
#include <vector>
#include <algorithm>
#include <string>// ... my code here ...Example, bad
#include <vector>// ... my code here ...#include <algorithm>
#include <string>Note
This applies to both .h and .cpp files.
Note
There is an argument for insulating code from declarations and macros in header files by #including headers after the code we want to protect (as in the example labeled "bad"). However
- that only works for one file (at one level): Use that technique in a header included with other headers and the vulnerability reappears.
- a namespace (an "implementation namespace") can protect against many context dependencies.
- full protection and flexibility require modules.
See also:
Enforcement
Easy.