More on Integers.

• Overflow, underflow
  • Your author defines overflow as when an arithmetic operator results in a number that is larger than the specified type can represent.
  • This is for magnitude, so there can be overflow for negative numbers as well.
• using
  • in c++, the using construct allows us to "nickname" a type.
  • using identifier = type-id;
  • This was done with typedef typeid identifier; in the past.
  • See this reference for using.
  • See this reference for typedef.
• An overflow program.
  • see overflow.cpp.
  • I added using MyIntTypeT = int; so I could change this easily.
  • Remember, convention says to name types in Camel case, but start with an upper case letter, and end with a T.
  • If I want, I can now change this to be any type I wish.
• I used limits to find the lowest and highest values, and added or subtracted one.
• make
  • Make is a utility on *nix that allows us to compile programs more easily
  • John will make extensive use of make next semester.
  • I want to start using it right now.
  • How many times have you messed up g++ -o ...
  • I can just type make overflow
  • And it will automatically do g++ -o overflow overflow.cpp, assuming that overflow.cpp exists in the directory.
• Output
  • With integers, output is fairly straight forward.
  • setw(int) works as expected.
  • setbase(int)
    • Unfortunately only works for bases 8, 10, 16.
  • Take a look at intOut.cpp.
• There are more output controls, but we will let those go for now.
• Integer input.
  • The tool is stream extraction (>>)
  • Like all stream extraction
    1. It skips whitespace.
    2. It attempts to read as much of an int as it can.
    3. When it stops,
       • if it was successful it stores a value in the int and the stream tests as true.
       • If it was not successful, and the stream tests as false.
         • and stores numeric_limits<type>::min().
• See intIn.cpp.