#include <iostream>

int main() {
	std::string test = "0:{src:'https://r...content-available-to-author-only...p.pl/token/video/vod/26773433/20180209/623845573/75e3c47b-fbed-47ae-88f6-aaab5762599e/video.ism/video.m3u8', type: 'application/x-mpegurl'},";
	std::size_t start = test.find("0:{src:'")+sizeof("0:{src:'")-1;
	std::size_t end = test.find(",", start) - 1;
	std::string link = test.substr(start, end - start);
	std::cout << link << '\n';
	return 0;
}