remove FILE_ATTRIBUTE_READONLY demo

demo.bat

:: Run this from a developer command prompt
type removeme.cpp
cl /EHsc /W4 /WX /std:c++17 .\removeme.cpp /Feremoveme
mkdir exampledir
:: owner == BUILTIN\Users
:: group == BUILTIN\Users
:: DACL: (note DACL processed in order)
::    (D;OICI;SD;;;BU) Deny, Object Inherit Container Inherit, DELETE, BUILTIN\Users
::    (D;OICI;0x40;;;WD) Deny, Object Inherit Container Inherit, FILE_DELETE_CHILD, WORLD\Everyone
::    (A;OICI;FA;;;BU) Allow, Object Inherit Container Inherit, FILE_ALL, BUILTIN\Users
cacls exampledir "/S:O:BUD:PAI(D;OICI;SD;;;BU)(D;OICI;0x40;;;WD)(A;OICI;FA;;;BU)"
echo "" > exampledir\examplefile
attrib +R exampledir\examplefile
.\removeme.exe exampledir\examplefile
dir /AR exampledir

removeme.cpp

#include <stdio.h>
#include <filesystem>
#include <system_error>

int wmain(int, wchar_t* argv[]) {
    std::error_code ec;
    std::filesystem::remove(argv[1], ec);
    if (ec) {
        puts(ec.message().c_str());
    }
}