Teach it how to deduce array signature

Author: rpavlik

jnipp.h

@@ -73,6 +73,7 @@ namespace jni
 
     // Foward Declarations
     class Object;
+    template <class TElement> class Array;
 
     /**
         This namespace is for messy implementation details only. It is not a part
@@ -103,6 +104,9 @@ namespace jni
         std::string valueSig(const Object* obj);
         inline std::string valueSig(const Object* const* obj) { return valueSig(obj ? *obj : nullptr); }
 
+        template <class TArg>
+        inline std::string valueSig(const Array<TArg>*) { return "[" + valueSig((TArg*) nullptr); }
+
         template <int n, class TArg>
         inline std::string valueSig(const TArg(*arg)[n]) { return valueSig((const TArg* const*)arg); }
 
@@ -223,10 +227,6 @@ namespace jni
      */
     JNIEnv* env();
 
-    // Forward declaration
-    template <class TElement>
-    class Array;
-
     /**
         Object corresponds with a `java.lang.Object` instance. With an Object,
         you can then call Java methods, and access fields on the Object. To

tests/main.cpp

@@ -307,11 +307,16 @@ TEST(Object_call_byNameWithArgs)
 TEST(Object_call_returningArray) {
     jni::Object str = jni::Class("java/lang/String").newInstance("Testing");
 
-    // TODO cannot deduce the right signature for an array
-    auto getBytes =
-        jni::Class("java/lang/String").getMethod("getBytes", "()[B");
-    auto bytes = str.call<jni::Array<jni::byte_t>>(getBytes);
-    ASSERT(bytes.getLength() == 7);
+    {
+        auto getBytes =
+            jni::Class("java/lang/String").getMethod("getBytes", "()[B");
+        auto bytes = str.call<jni::Array<jni::byte_t>>(getBytes);
+        ASSERT(bytes.getLength() == 7);
+    }
+    {
+        auto bytes = str.call<jni::Array<jni::byte_t>>("getBytes");
+        ASSERT(bytes.getLength() == 7);
+    }
 }
 
 TEST(Object_makeLocalReference)