Add the indexMultiply C++ def (yet to implement) in the pyfaust wrapper.

wrapper/python/src/FaustCoreCppGPU.cpp.in

@@ -106,7 +106,14 @@ FaustCoreCpp<@TYPE@,GPU2>* FaustCoreCpp<@TYPE@,GPU2>::read_from_mat_file(const c
 }
 
 template<>
-void FaustCoreCpp<@TYPE@,GPU2>::colSliceMultiply(unsigned long int j1, unsigned long int j2, const @TYPE@* vec_data, @TYPE@* vec_out) const
+void FaustCoreCpp<@TYPE@,GPU2>::colSliceMultiply(unsigned long int j1, unsigned long int j2, const @TYPE@* data, unsigned long int data_ncols, @TYPE@* out) const
 {
-    throw std::runtime_error("sliceMultiply is not yet supported on GPU");
+    throw std::runtime_error("colSliceMultiply is not yet supported on GPU");
+}
+
+template<>
+void FaustCoreCpp<@TYPE@,GPU2>::indexMultiply(unsigned long int* ids, size_t ids_len, const @TYPE@* vec_data, @TYPE@* vec_out) const
+{
+
+    throw std::runtime_error("indexMultiply is not yet supported on GPU");
 }