Accelerated C++ 5 Using sequential containers and analyzing strings

The<cctype>header provides useful functions for manipulating charactor data:

isspace(c)isalpha(c)isdigit(c)isalnum(c)ispunct(c) // punctuation charactorisupper(c)islower(c)toupper(c)tolower(c)

I.

split.h

#ifndef GUARD_split_h#define GUARD_split_h#include <vector>#include <string>std::vector<std::string> split(const std::string&);#endif

split.cpp

//source file split-related#include<cctype>#include "split.h"using std::string; using std::vector;vector<string> split(const string& s) {    vector<string> ret;    typedef vector<string>::size_type s_sz;    s_sz i = 0;    s_sz j = 0;    while (i != s.size()) {        while (i != s.size() && isspace(s[i]))            ++i;        j = i;        while (j != s.size() && !isspace(s[j]))            ++j;        if (i != j) {            ret.push_back(s.substr(i,j - i));            i = j;        }    }    return ret;}

I.

Student_info.h
Student_info.cpp
grade.h(median.h)
grade.cpp(median.cpp)
see Note 4

extract_fails.h

#ifndef GUARD_extract_fails_h#define GUARD_extract_fails_h#include <list>#include "Student_info.h"bool fgrade(const Student_info&);bool pgrade(const Student_info&);std::list<Student_info> extract_fails(std::list<Student_info>&); #endif

extract_fails.cpp

#include "grade.h"#include "extract_fails.h"#include "fopgrade.h"#include "Student_info.h"using std::list;bool fgrade(const Student_info& s) {    return grade(s) < 60;}bool pgrade(const Student_info& s) {    return grade(s) >= 60;}list<Student_info> extract_fails(list<Student_info>& students) {    list<Student_info> fails;    list<Student_info>::iterator iter = students.begin();    while(iter != students.end()){        if (fgrade(*iter)) {            fails.push_back(*iter);            iter = students.erase(iter);        } else {            ++iter;        }    }    return fails;}

main.cpp

#include <algorithm>#include <iomanip>  // setprecision#include <ios>      // streamsize   #include <iostream>#include <stdexcept>#include <string>#include "Student_info.h"#include "grade.h"#include "extract_fails.h"using std::list;            using std::sort;    using std::string;  using std::endl;using std::domain_error;    using std::cin;     using std::cout;    using std::max;using std::streamsize;      using std::setprecision; using std::list; using std::setw;int main(){    list<Student_info> students;    Student_info record;    list<Student_info> fail_stus;    string::size_type maxlen = 0;    // read and store all the students' data    // Invariant: students contains all the student records read so far    //            maxlen contains the length of the longest name in students    while (read(cin, record)) {        // find length of longest name        maxlen = max(maxlen, record.name.size());        students.push_back(record);    }    // alphabetize the student records    sort(students.begin(), students.end(), compare);    // write the names and grades    for (list<Student_info>::iterator it = students.begin(); it != students.end(); ++it){        // write the name, padded on the right to maxlen + 1 characters        record = (*it);        cout << record.name << string(maxlen + 1 - record.name.size(), ' ');        // compute and write the grade        try {            double final_grade = grade(record);            streamsize prec = cout.precision();            cout << setprecision(3) << final_grade << setprecision(prec);        } catch (domain_error e) {            cout << e.what();        }        cout << endl;    }    cout << "print the students who fail the exam!" << endl;    fail_stus = extract_fails(students);    for (list<Student_info>::iterator it = fail_stus.begin(); it != fail_stus.end(); ++it) {        record = *it;        cout << record.name << string(maxlen + 1 - record.name.size(), ' ');        try {            streamsize prec = cout.precision();            cout << setw(4) << setprecision(3) << grade(record) << setprecision(prec);        } catch (domain_error e) {            cout << e.what();        }        cout << endl;    }    return 0;}