something alike:

std::regex e ("("name.c_str()")(.*)");

is wrong. any ideas?

fastcall22 has addressed that issue above already, with example code of what is wrong and how to make it work.

Again, I want to list all beginning with the string "name".

Something alike:

std::regex e ("^"name);

is wrong. Moderators, if it's that easy, why don't you give the correct code and not some unusable handicrafts?

But you have been given the correct solution already; see fastcall22's post above. If you don't understand it, then ask for clarification and we may answer to help you learn why and how it works, but spoon feeding a solution is not helping anyone.

Aah ok got it, thanks.