need 4 items to format a number
- format (fixed/scientific/general)
- width
- precision
- left/right (default is right, but suppose had used 'left' earlier
  for a string)

fixed, scientific, general:  (see precision2.cpp)
- fixed = business format (fixed no. of decimal places)
- scientific = scientific notation (mantissa/exponent)
- general = fixed for small nos., scientific for large
- default is general
- fixed and scientific reset each other
- to return to general, resetiosflags(ios::fixed | ios::scientific)
  or cout.unsetf(ios::fixed | ios::scientific)

setw():  (see width2.cpp)
- only manipulator that is not sticky/persistent
- default is setw(0) = no spaces between numbers
- if number is too large, it forces columns to move over

precision():  (see point1.txt and justify5.cpp)
- fixed: no. of decimal places
- scientific: no. of decimal places in mantissa
- general: total no. of digits (on this compiler)
- default is setprecision(6)   (see precision2.cpp)

left and right:  (see justify5.cpp)
- left and right reset each other (also internal, see below)
- default is right
- usually want 'left' for strings, then need 'right' for following number

setfill:  (see manip1.cpp)
- setfill('*') for checks
- setfill('0') for ID nos.
- setfill('0') for hex (see below)
- default is setfill(' ')
- setfill doesn't work with negative numbers (not intended for that) 
  unless internal justification is used (see below)

showpoint:  (see point1.txt)
- only affects general format: forces decimal point, and precision as above
- also affects fixed when precision=0: forces decimal point  (see mods2.cpp)
- default is noshowpoint

showpos:  (see manip1.txt)
- forces '+'
- default is noshowpos

internal justification:  (see manip2.txt)
- forces sign in separate column on the left
- left, right, and internal reset each other

dec, hex, showbase:  (see mods2.cpp)
- hex = show number in hex
- showbase = puts 0x before hex number
- may also need setfill('0') to get full 8-digit hex

boolalpha:  (see bool6.cpp)
- display true and false instead of 1 and 0

what needs to be included:
- all need #include <iostream>
- manipulators with arguments need <iomanip>