1 files changed, 50 insertions, 0 deletions
diff --git a/platform/android/src/conversion/conversion.hpp b/platform/android/src/conversion/conversion.hpp
new file mode 100644
index 0000000000..ea8a31bcf2
--- /dev/null
+++ b/platform/android/src/conversion/conversion.hpp
@@ -0,0 +1,50 @@
+#pragma once
+
+#include <mbgl/util/variant.hpp>
+
+#include <jni/jni.hpp>
+
+#include <string>
+
+namespace mbgl {
+namespace android {
+namespace conversion {
+
+struct Error { std::string message; };
+
+template <class T>
+class Result : private variant<T, Error> {
+public:
+    using variant<T, Error>::variant;
+
+    explicit operator bool() const {
+        return this->template is<T>();
+    }
+
+    T& operator*() {
+        assert(this->template is<T>());
+        return this->template get<T>();
+    }
+
+    const T& operator*() const {
+        assert(this->template is<T>());
+        return this->template get<T>();
+    }
+
+    const Error& error() const {
+        assert(this->template is<Error>());
+        return this->template get<Error>();
+    }
+};
+
+template <class T, class V>
+struct Converter;
+
+template <class T, typename V, class...Args>
+Result<T> convert(jni::JNIEnv& env, const V& value, Args&&...args) {
+    return Converter<T, V>()(env, value, std::forward<Args>(args)...);
+}
+
+} // namespace conversion
+} // namespace android
+} // namespace mbgl
+\ No newline at end of file