Function MultipartEncode

http.cpp:178–229

	vector<uint8_t> MultipartEncode(const vector<MultipartField>& fields, string& boundary)
	{
		boundary = string(4, '-') + "MultipartFormBoundary" + (string)BNGetUniqueIdentifierString();

		vector<uint8_t> boundaryVec;
		boundaryVec.reserve(boundary.size());
		copy(boundary.begin(), boundary.end(), back_inserter(boundaryVec));

		vector<uint8_t> result;
		size_t expectedSize = boundaryVec.size() * fields.size();
		for (const auto& field : fields)
		{
			expectedSize += field.name.size() + field.content.size();
		}
		result.reserve(expectedSize);

		for (const auto& field : fields)
		{
			result.push_back('-');
			result.push_back('-');
			copy(boundaryVec.begin(), boundaryVec.end(), back_inserter(result));
			result.push_back('\r');
			result.push_back('\n');
			string disposition;
			if (field.filename)
			{
				disposition = string("Content-Disposition: form-data; name=\"") + field.name + "\"; filename=\""
				              + *field.filename + "\"";
				disposition += string("\r\nContent-Type: application/octet-stream");
			}
			else
			{
				disposition = string("Content-Disposition: form-data; name=\"") + field.name + "\"";
			}
			disposition += "\r\n\r\n";

			copy(disposition.begin(), disposition.end(), back_inserter(result));
			copy(field.content.begin(), field.content.end(), back_inserter(result));

			result.push_back('\r');
			result.push_back('\n');
		}
		result.push_back('-');
		result.push_back('-');
		copy(boundaryVec.begin(), boundaryVec.end(), back_inserter(result));
		result.push_back('-');
		result.push_back('-');
		result.push_back('\r');
		result.push_back('\n');

		return result;
	}


	Request::Request(string method, string url, const unordered_map<string, string>& headers,