Implemented parsing of ASCII arrays in the XMLVTK class

      return found;

   }

   template< typename T >

   VariantVector

   readAsciiBlock( const char* block ) const

   {

      // creating a copy of the block is rather costly, but so is ASCII parsing

      std::stringstream ss;

      ss << block;

      std::vector<T> vector;

      while( ss ) {

         // since std::uint8_t is an alias to unsigned char, we need to parse

         // bytes into a larger type, otherwise operator>> would read it as char

         std::common_type_t< T, std::uint16_t > value;

         ss >> value;

         if( ss )

            vector.push_back( value );

      }

      return vector;

   }

   template< typename HeaderType >

   static std::size_t

   readBlockSize( const char* block )

      const std::string type = getAttributeString( elem, "type" );

      const std::string format = getAttributeString( elem, "format" );

      if( format == "ascii" ) {

         // TODO

         throw MeshReaderError( "XMLVTK", "reading ASCII arrays is not implemented yet" );

         if( type == "Int8" )          return readAsciiBlock< std::int8_t   >( block );

         else if( type == "UInt8" )    return readAsciiBlock< std::uint8_t  >( block );

         else if( type == "Int16" )    return readAsciiBlock< std::int16_t  >( block );

         else if( type == "UInt16" )   return readAsciiBlock< std::uint16_t >( block );

         else if( type == "Int32" )    return readAsciiBlock< std::int32_t  >( block );

         else if( type == "UInt32" )   return readAsciiBlock< std::uint32_t >( block );

         else if( type == "Int64" )    return readAsciiBlock< std::int64_t  >( block );

         else if( type == "UInt64" )   return readAsciiBlock< std::uint64_t >( block );

         else if( type == "Float32" )  return readAsciiBlock< float  >( block );

         else if( type == "Float64" )  return readAsciiBlock< double >( block );

         else throw MeshReaderError( "XMLVTK", "unsupported DataArray type: " + type );

      }

      else if( format == "binary" ) {

         if( type == "Int8" )          return readBinaryBlock< std::int8_t   >( block );