gsub.cc

#include <string>
#include <vector>
#include <utility>

void gsub(std::string& str, std::vector< std::pair< std::string, std::string >> substitutions)
{
	for(const auto& sub : substitutions)
	{
		const std::string& from = sub.first;
		const std::string& to = sub.second;

		for(std::size_t i = 0; i < str.size(); )
		{
			i = str.find(from, i);
			if(i != std::string::npos)
			{
				str.replace(i, from.size(), to);
				i += to.size();
			}
		}
	}
}

#include <cassert>

void test_gsub()
{
    std::string json = R"json({"x": 1, "b": "yolo'n't"})json";
    gsub(json, { {"\"", "\\\""}, {"'", "\\'"} });
    assert(json == "{\\\"x\\\": 1, \\\"b\\\": \\\"yolo\\'n\\'t\\\"}");
}