Canonical main() signature

Axiom 1

Unnecessary (!) global variables are evil.

Definition 1 : legacy C style main() function with arguments signature

int main(int argc, char** argv)

Definition 2 : const-correct main() function with arguments signature

int main(const int argc, char const * const * const argv)

Theorem 1

Any non-const function parameter is global variable within function body.

Theorem 2

Using legacy C style main() function with arguments signature is almost always (!) evil.

Theorem 3

Using const-correct main() function with arguments signature is much less evil (for certain values of much).

Any non-obvious theorems are to be proved as homework.

Codification of main()

ISO/EIC 14882 3.6.1 2

... It [main function] shall have a return type of type int, but otherwise its type is implementation-defined. All implementations shall allow both of the following definitions of main:

int main() { /* ... */ }

and

int main(int argc, char* argv[]) { /* ... */ }

Does holy ISO/EIC 14882 really say evil is omnipresent and doom inevitable?!

That was real close but hell no!

Const and volatile qualifiers in function signatures

Hidden in large tome of ISO/EIC 14882 is the magical fine-print: const in function signature does not count when function type matters.

ISO/EIC 14882:1998 8.3.5 3

... The type of a function is determined using the following rules. The type of each parameter is determined from its own decl-specifier-seq and declarator. ... Any cv-qualifier modifying a parameter type is deleted. [Example: the type void(*)(const int) becomes void(*)(int) -end example] Such cv-qualifiers affect only the definition of the parameter within the body of the function; they do not affect the function type. ...

ISO/EIC 14882:2011 8.3.5 5

... After producing the list of parameter types, any top-level cv-qualifiers modifying a parameter type are deleted when forming the function type. ...

Moral

• Cv-qualifiers of function arguments does not affect signature.
• ISO/EIC 14882 suggests but luckily does not enforce legacy C style main function.
• There are some "Hello, World!" tutorials to be fixed. Quite a few actually.