...
In C++ the usage of foo() and foo(void) has exactly the same meaning and effect, so this rule doesn't apply to C++.
But it is still recommended to explicitly declare foo(void) instead of foo() to distinguish from foo(...), which will then takes arbitrary parameters.
References
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\[[ISO/IEC 9899:1999|AA. C References#ISO/IEC 9899-1999]\] Forward and Section 6.9.1, "Function definitions" |