The snippet below illustrates what I am trying to do. I get an assertion error message. TIA, -RFH -------------------- typedef boost::multi_array ExpressionArrayType; map truthTable; ExpressionArrayType exprTable(boost::extents[50][50]); // initial size irrelevant for (some iterator that provides changing array dimensions here) { exprTable.resize(boost::extents[new_nof_rows][new_nof_cols]); truthTable[subscript] = exprTable; <-- Assertion fails }