Minor fixes + tests + getSupportURL().

tests/python/test_qt.cpp

@@ -0,0 +1,59 @@
+#include "pybind11_qt/pybind11_qt.h"
+
+#include <pybind11/pybind11.h>
+
+using namespace pybind11::literals;
+
+PYBIND11_MODULE(qt, m)
+{
+    // QString
+
+    m.def("qstring_to_stdstring", [](QString const& qstring) {
+        return qstring.toStdString();
+    });
+
+    m.def("stdstring_to_qstring", [](std::string const& string) {
+        return QString::fromStdString(string);
+    });
+    m.def("qstring_to_int", [](QString const& qstring) {
+        return qstring.toInt();
+    });
+    m.def("int_to_qstring", [](int value) {
+        return QString::number(value);
+    });
+
+    // QStringList
+
+    m.def("qstringlist_join", [](QStringList const& values, QString const& sep) {
+        return values.join(sep);
+    });
+
+    m.def("qstringlist_at", [](QStringList const& values, int index) {
+        return values.at(index);
+    });
+
+    // QMap
+    m.def("qmap_to_length", [](QMap<QString, QString> const& map) {
+        QMap<QString, int> res;
+        for (auto it = map.begin(); it != map.end(); ++it) {
+            res[it.key()] = it.value().size();
+        }
+        return res;
+    });
+
+    // QDateTime
+
+    m.def(
+        "datetime_from_string",
+        [](QString const& date, Qt::DateFormat format) {
+            return QDateTime::fromString(date, format);
+        },
+        "string"_a, "format"_a = Qt::DateFormat::ISODate);
+
+    m.def(
+        "datetime_to_string",
+        [](QDateTime const& datetime, Qt::DateFormat format) {
+            return datetime.toString(format);
+        },
+        "datetime"_a, "format"_a = Qt::DateFormat::ISODate);
+}