c++ is quite hard to decompile, java .net and all “bitcode” languages are very easy to decompile and you must use an obfuscator to protect it, a little.
skimming through the tutorials I read ue4 uses bitcode though?, is that for blueprints? If you start a c++ project will it be completely compiled to machine code? or will any blueprints you use be possible to decompile?