Manipulators for floating-point data types

• showpoint: insert a decimal point unconditionally in a generated floating-point field.

• fixed: insert floating-point values in fixed-point format. For example, default format for 1234.56789 is 1234.57, fixed makes it 1234.56789.

• scientific: insert floating-point values in scientific format with an exponent field. For example, default format for 1234.56789 is 1234.567, scientific makes it 1.234568e+03.