I don't think there's a recommended order, as long as it compiles! What's annoying is when some headers require other headers to be included ...
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Ideally, all header files should be self-contained, and inclusion order
Learn more about: Header files (C++)
Order is of little importance, except if you make a great use of macros and #define ; in that case, you must
Except for the main module, each source (.c) file has a header file (a “.h”
Rules for managing header file includes in C++
The order of system header file includes is usually not important.
Each program requires at least one header file to work. Before we begin our discussion, it is important to understand, what are preprocessor directives? These are ...
Include headers in the following order: Related header, C system headers, C++ ...
In order to use this header file in main.cpp, we have to #include it (using quotes, not angle brackets). main.cpp: ...