diff -r 46151cd23815 -r 9d566568d37c src/Iconv.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Iconv.cpp	Wed Nov 20 14:56:41 2019 +0100
@@ -0,0 +1,82 @@
+/**
+ * Relational pipes (library)
+ * Copyright © 2019 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the:
+ *  - GNU Lesser General Public License as published by the Free Software Foundation;
+ *    version 3 of the License or (at your option)
+ *  - GNU General Public License as published by the Free Software Foundation;
+ *    version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "../include/relpipe/common/text/Iconv.h"
+
+namespace relpipe {
+namespace common {
+namespace text {
+
+class Iconv::IconvInternal {
+public:
+	static const size_t BUFFER_SIZE_MINIMUM;
+	static const size_t BUFFER_SIZE_DEFAULT;
+	const size_t bufferSize;
+	iconv_t cd;
+
+	IconvInternal(std::string to, std::string from, const size_t bufferSize) : bufferSize(std::max(bufferSize, BUFFER_SIZE_MINIMUM)) {
+		cd = iconv_open(to.c_str(), from.c_str());
+		if (errno) throw std::string("iconv_open() error: ") + strerror(errno); // TODO: custom exception
+	}
+
+	virtual ~IconvInternal() {
+		iconv_close(cd);
+	}
+
+};
+
+const size_t Iconv::IconvInternal::BUFFER_SIZE_MINIMUM = 2;  // TODO: enough?
+const size_t Iconv::IconvInternal::BUFFER_SIZE_DEFAULT = 20;
+
+Iconv::Iconv(std::string to, std::string from) : Iconv(to, from, IconvInternal::BUFFER_SIZE_DEFAULT) {
+}
+
+Iconv::Iconv(std::string to, std::string from, size_t bufferSize) {
+	internal = new Iconv::IconvInternal(to, from, bufferSize);
+
+}
+
+Iconv::~Iconv() {
+	delete internal;
+}
+
+std::string Iconv::convert(std::string originalText) {
+	std::stringstream result;
+	size_t inBytesLeft = originalText.size();
+	size_t outBytesLeft = internal->bufferSize;
+	char outBuffer[internal->bufferSize];
+	char* outBuf = (char*) outBuffer;
+	char* inBuf = (char*) originalText.c_str();
+
+	do {
+		size_t nconv = iconv(internal->cd, &inBuf, &inBytesLeft, &outBuf, &outBytesLeft);
+		if (nconv < 0) throw std::string("iconv() error: ") + strerror(errno); // TODO: custom exception
+		// TODO: throw exception if locale is not initialized and platform default "" is used (avoid infinite loop)
+		result.write(outBuffer, internal->bufferSize - outBytesLeft);
+		outBytesLeft = internal->bufferSize;
+		outBuf = (char*) outBuffer;
+	} while (inBytesLeft > 0);
+
+	return result.str();
+}
+
+}
+}
+}