no. many of the improvements to c++ were things that were just not possible in c++ before. that's why they were added. you can probably still express just about any idea you want in older versions just probably not as well if they are actually using features of c++11. that being said a lot of code will work with compilers targeting c++11 and older versions so you could just try to compile it with an older language spec. then you look and see if it spits out any errors. if it does you go to that line and re-write that part with changes that meet the old spec. and hit compile again. repeat until it works. You can write new code in older language specs and just call c++11/14/17 code that's already compiled. no problem there either.