CS253 HW8: Container!                

Description                

For this assignment, you will make the U class a (somewhat) STL-compatible container, by adding several methods and a type.                 

Methods                

Your U class must have the same methods as described in HW7, and:                 

U methods & type:                

• U(iter, iter)
  A constructor that takes a pair of iterators. The two iterators must describe a half-open range, and yield char upon indirection. The iterators are not the same type as U::iterator. Instead, they are iterators of any type, where *iter yields a char. The initial value of the U object is created from the string described by the half-open range, as if .append() were used. Throw a std::string error message for the same reasons that .append() does.
• .begin()
  Returns a U::iterator that “points” to the first int codepoint.
• .end()
  Returns a U::iterator that “points” just past the last int codepoint.
• U::iterator
  An iterator type. It iterates through the int codepoints accumulated in the U object.
• .front()
  Returns the first int codepoint by value. Throw a std::string error message if not available.
• .back()
  Returns the last int codepoint by value. Throw a std::string error message if not available.

U::iterator methods:                

• default ctor
• copy ctor
• assignment operator
• dtor
• iter==iter
• iter!=iter
• pre-/post-increment/decrement
• *iter (yields an int codepoint by value)

No error-checking is required for iterator methods.                 

Const-correctness, both arguments & methods, is your job. For example, it must be possible to call .begin() on a const U.                 

Sample Run                

Here is a sample run, where % is my shell prompt:                 

    % cat main.cc
    #include "U.h"
    #include <iostream>
    #include <cassert>

    using std::cout;
    using std::hex;
    using std::showbase;

    int main() {
        const char s[] = "\U0001f382 × 11 \u21d2 9\u00be";

        U u(s, s+sizeof(s)-1);
        assert(u == "\U0001f382 × 11 \u21d2 9\u00be");
        cout << u << '\n';			// 🎂 × 11 ⇒ 9¾

        assert(u.front() == 0x1f382);		// birthday cake
        assert(u.back() == 0xbe);		// three-quarters
        U::iterator it = u.begin();
        assert(*it == 0x1f382);			// birthday cake
        it++;
        assert(*it == ' ');
        it = u.end();
        --it;
        assert(*it == 0xbe);			// ¾

        for (auto cp : u)
            cout << hex << showbase << cp << ' ';
        cout << '\n';
    }
    % g++ -Wall main.cc U.cc
    % ./a.out
    🎂 × 11 ⇒ 9¾
    0x1f382 0x20 0xd7 0x20 0x31 0x31 0x20 0x21d2 0x20 0x39 0xbe 

Requirements                

The requirements are the same as HW7, plus the methods and types shown above.                 

Ask                

If you have any questions about the requirements, ask. In the real world, your programming tasks will almost always be vague and incompletely specified. Same here.                 

How to submit your homework:                

You will turn in at least two files:

• U.h: the interface for class U
• U.cc: the implementation for class U
• plus whatever other *.cc and *.h files you require.
• Don’t turn in a main function or main.cc.
• Don’t turn in a Makefile.

That’s a lot of files, so construct a tar file, like this:

    tar -cvf hw8.tar U.cc U.h other-files …

and turn it in.                 

Use web checkin, or Linux checkin:                 

    ~cs253/bin/checkin HW8 hw8.tar

How to receive negative points:                

Turn in someone else’s work.