No, you can't... [realloc()][1]realloc() can only be used with malloc()/free()
Best call for a new[] allocated array is to create a new one and then memcpy() the data from one to another.
Better way - use an [std::vector][2]std::vector or [std::string][3]std::string instead of array if you know you'll need resizing. Internally they're pretty much the same array.