regex_demo.cpp

#include <algorithm>
#include <iostream>
#include <cctype>
#include <regex>

int main()
{
    std::string str("server\t\n{ a = 5; b ={ a }  c = what; } \nisthatthe{ case; }");
    //str.erase(remove_if(str.begin(), str.end(), isspace), str.end());

    std::regex expr("([^]+?)\\{([^]+?)\\}");

    std::smatch matches;

    for (std::sregex_iterator it(str.begin(), str.end(), expr), end_it; it != end_it; it++) {
        std::cout << ">>>>>> START <<<<<<<" << std::endl;
        std::cout << it->str() << std::endl;
        std::cout << ">>>>>> END <<<<<<<" << std::endl;
    }
    /*if (std::regex_search(str, matches, expr)) {
        for (size_t i = 1; i < matches.size(); i++) {
            std::string match(matches[i].first, matches[i].second);
            std::cout << "matches[" << i << "] = " << match << std::endl;
        }
    }*/
    return 0;
}

std::string s = "text here++ text\n# text text\n# text\ntext text";
	std::regex r("#([^]+?)\\n");
	std::cout << std::regex_replace(s, r, "") << std::endl;
	return 0;

https://www.codeproject.com/Articles/11556/Converting-Wildcards-to-Regexes