It’s not allowed, because as per the standard 21.4.1 p6, invalidation of iterators/references is only allowed for — as an argument to any standard library function taking a reference to non-const basic_string as an argument. — Calling non-const member functions, except operator[], at, front, back, begin, rbegin, end, and rend. For a COW string, calling … Read more
std::string doesn’t contain such function but you could use stand-alone replace function from algorithm header. #include <algorithm> #include <string> void some_func() { std::string s = “example string”; std::replace( s.begin(), s.end(), ‘x’, ‘y’); // replace all ‘x’ to ‘y’ }
Modern C++ makes this super simple. C++20 C++20 introduces std::format, which allows you to do exactly that. It uses replacement fields similar to those in python: #include <iostream> #include <format> int main() { std::cout << std::format(“Hello {}!\n”, “world”); } Code from cppreference.com, CC BY-SA and GFDL Check out the compiler support page to see if it’s … Read more
How to trim a std::string?
You should do int error=regexec(®ex,cppstring.c_str(),nmatch,pmatch,eflags); The second argument of regexec() and the return value of std::string::c_str() are both (const char *), so that’s probably not the cause of your issue. You should post the compiler error message and the part of the code that you suspect to be causing the problem.
std::strings are much easier to work with than char arrays for beginners. I’d suggest you use them unless there is a reason not to. There are many issues with the code. See if you can get less code working first. How about one function that you call from main, passing in stings and char array … Read more