we create new softwares using c++ ,but How and with what was c++ build?

Answer 1

With one of the languages that existed before. I'd assume C as Bjarne Stroustrup, the inventor of C++, must have known C quite well to construct a language as C++ that accepts C code.
Even today, g++ and llvm/clang++ are written in C. Nevertheless, you could write a C++ compiler in C++, use another C++ compiler to build your first binary and from then on only use your own compiler to compile the new version of your own compiler. :-)

Answer 2

Well, Stefan, C was made by Dennis Ritchie, not Bjarne Stroustrup. also making g++ and clang with c++ is the similar concept with making PyPy.

Answer 3

@GeoDash: I was not talking about Bjarne Stroustrup inventing C. I talked about *probably* C being used by Bjarne Stroustrup to write the (first) C++ compiler.
Furthermore I did not display compiling C++ by a C++ compiler as something novel. I hinted that I find the idea interesting by ":-)". Meanwhile quite some interpreters use this the "run the program with a program written in the same programming language".

Answer 4

aha. so The concept is still similar with PyPy, right?

Answer 5

@GeoDash: Yes, it is.