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我正在爲一個有理數的類實現一個類，這當然涉及覆蓋像'=='和'！='這樣的常見操作符。我很確定在我失蹤的地方有一個愚蠢的錯誤，不要猶豫，要求提供任何我沒有提供的文件。謝謝！C++：重寫操作符時的多重定義
rational.hpp：
#ifndef RATIONAL_HPP
#define RATIONAL_HPP
#include "test.hpp"
#include <cstdlib>
#include <iosfwd>
#include <iostream>
#include <assert.h>
// Mathematical helper functions.
//
// NOTE: These are defined in rational.cpp.
int gcd(int, int);
int lcm(int, int);
// Represents a rational number. The rational numbers are the set of
// numbers that can be represented as the quotient of two integers.
struct Rational
{
// TODO: Define the following:
// 1. A default constructor
int n;
int d;
Rational()
:n(0), d(1) {}
// 2. A constructor that takes an integer value
Rational(int num)
:n(num), d(1){}
// 3. A constructor that takes a pair of values
Rational(int numer, int denom)
:n(numer), d(denom) {
assert(d != 0);
int gcdnum;
if ((numer % denom) != 0){
//do nothing
}else{
gcdnum = gcd(numer, denom);
numer /= gcdnum;
denom /= gcdnum;
Rational(numer, denom);
}
}
// Returns the numerator.
int num() const {
return n;
}
// Returns the denominator
int den() const {
return d;
}
};
bool operator==(Rational a, Rational b){
return (a.n == b.n && a.d == b.d);
}
bool operator!=(Rational a, Rational b){
return (a.n != b.n && a.d != b.d);
}
bool operator < (Rational a, Rational b){
int lcdNum = lcm(a.d, b.d);
int newAN, newBN; //allows for comparisons without altering actuial value
newAN = a.n * lcdNum;
newBN = b.n * lcdNum;
return newAN < newBN;
}
bool operator > (Rational a, Rational b){
int lcdNum = lcm(a.d, b.d);
int newAN, newBN; //allows for comparisons without altering actuial value
newAN = a.n * lcdNum;
newBN = b.n * lcdNum;
return newAN > newBN;
}
bool operator <= (Rational a, Rational b){
int lcdNum = lcm(a.d, b.d);
int newAN, newBN; //allows for comparisons without altering actuial value
newAN = a.n * lcdNum;
newBN = b.n * lcdNum;
return newAN <= newBN;
}
bool operator >= (Rational a, Rational b){
int lcdNum = lcm(a.d, b.d);
int newAN, newBN; //allows for comparisons without altering actuial value
newAN = a.n * lcdNum;
newBN = b.n * lcdNum;
return newAN >= newBN;
}
// 3. The standard arithmetic operators
// - r1 + r2
// - r1 - r2
// - r1 * r2
// - r1/r2
// - r1/r2
Rational operator + (Rational a, Rational b){
int lcdNum = lcm(a.d, b.d);
int newAN, newBN; //allows for comparisons without altering actuial value
newAN = a.n * lcdNum;
newBN = b.n * lcdNum;
Rational c((newAN + newBN), (a.d * lcdNum));
return c;
}
Rational operator - (Rational a, Rational b){
int lcdNum = lcm(a.d, b.d);
int newAN, newBN; //allows for comparisons without altering actuial value
newAN = a.n * lcdNum;
newBN = b.n * lcdNum;
Rational c((newAN + newBN), (a.d * lcdNum));
return c;
}
Rational operator * (Rational a, Rational b){
Rational c((a.n * b.n), (a.d * b.d));
return c;
}
Rational operator/(Rational a, Rational b){
Rational c((a.n * b.d), (a.d * b.n)); //multiplies by the reciprocal
return c;
}
std::ostream& operator<<(std::ostream&, Rational);
std::istream& operator>>(std::istream&, Rational&);
#endif
rational.cpp：
//
// rational.hpp: Definition of rational class and its interace.
#include "rational.hpp"
#include <iostream>
// -------------------------------------------------------------------------- //
// Helper functions
// Compute the GCD of two integer values using Euclid's algorithm.
int
gcd(int a, int b)
{
while (b != 0) {
int t = b;
b = a % b;
a = t;
}
return a;
}
// Compute the LCM of two integer values.
int
lcm(int a, int b)
{
return (std::abs(a)/gcd(a, b)) * std::abs(b);
}
// -------------------------------------------------------------------------- //
// Rational implementation
// TODO: Make this print integers when the denominator is 1.
std::ostream&
operator<<(std::ostream& os, Rational r)
{
if(r.den() == 1){
return os << r.num();
}else{
return os << r.num() << '/' << r.den();
}
}
// TODO: Make this read integer values if no '/' is given as a separator.
// You may assume that there is no space between the numerator and the
// slash. Hint, find and read the reference documentation for istream::peek().
std::istream&
operator>>(std::istream& is, Rational& r)
{
int p, q;
char c;
is >> p;
c = is.peek();
if (c == '/'){
is >> c >> q;
if (!is)
return is;
// Require that the divider to be a '/'.
if (c != '/') {
is.setstate(std::ios::failbit);
return is;
}
// Make sure that we didn't read p/0.
if (q == 0) {
is.setstate(std::ios::failbit);
return is;
}
r = Rational(p, q);
return is;
}else{
is.setstate(std::ios::failbit);
}
}
rc.cpp：
// main.cpp: rational number test suite
#include "rational.hpp"
#include <iostream>
#include <iomanip>
#include <unistd.h>
int
main()
{
// Determine if input is coming from a terminal.
bool term = isatty(0);
// This will continue reading until it reaches the end-of-input.
// If you are using this interactivly, type crtl-d to send the
// end of input character to the terminal.
while (std::cin) {
Rational r1;
Rational r2;
std::string op;
if (term)
std::cout << "> ";
std::cin >> r1 >> op >> r2;
if (!std::cin)
break;
// FIXME: Add all of the other overlaoded operators by adding
// cases for each of them.
if (op == "==")
std::cout << std::boolalpha << (r1 == r2) << '\n';
else if (op == "!=")
std::cout << std::boolalpha << (r1 != r2) << '\n';
else if (op == "<")
std::cout << std::boolalpha << (r1 < r2) << '\n';
else if (op == ">")
std::cout << std::boolalpha << (r1 > r2) << '\n';
else if (op == "<=")
std::cout << std::boolalpha << (r1 <= r2) << '\n';
else if (op == ">=")
std::cout << std::boolalpha << (r1 >= r2) << '\n';
else if (op == "+")
std::cout << (r1 + r2) << '\n';
else if (op == "-")
std::cout << (r1 - r2) << '\n';
else if (op == "*")
std::cout << (r1 * r2) << '\n';
else if (op == "/")
std::cout << (r1/r2) << '\n';
else
std::cerr << "invalid operator: " << op << '\n';
}
// If we got to the end of the file without fatal errors,
// return success.
if (std::cin.eof())
return 0;
// Otherwise, diagnose errors in input and exit with an error
// code.
if (std::cin.fail()) {
std::cerr << "input error\n";
return 1;
}
return 0;
}
你得到的錯誤是什麼？你能對這個問題更具體嗎？ – 0x499602D2