类异常和操作符
我很难让很多操作员工作
分配说明如下
这项任务的目的是处理例外情况。 您可能还记得，我已经为您提供了一个名为FlashDrive的示例类，该示例的示例如下。 您可以在此获取FlashDrive类的源代码（.NET或.NET 2010）我希望您能够增强此类，以便调用其方法或操作符可能会引发异常，而不仅仅是将错误消息打印到cout。 目前，我们最喜欢的异常类是std :: logic_error。 您可以通过将字符串值传递给其构造函数来创建logic_error。 正式的，你也应该说#include开始使用logic_error，但Visual Studio（作为一个表现不好的孩子......）让你离开它。 一旦你完全正确地工作，驱动程序代码应该按照课程中的描述运行。
虽然示例驱动程序代码可能不适用于所有这些情况，但我希望在下列情况下引发异常：
更多的东西已经放在驱动器上比它可以安全地保存（由于writeData）
负数可能被用作my_StorageUsed值（由于运算符 - 或者将错误值发送给构造函数调用）
负数可能被用作my_StorageCapacity值（由于操作符 - 或者将错误的值发送给构造函数调用）所以请仔细考虑所有类的运算符和方法，以确保在这些情况下引发logic_error。
我也想让你的操作符<<和operator >>为FlashDrive类工作。 最后，我想让你将FlashDrive放入命名空间cs52。
以下是我的代码和构建输出
FlashDrive.h
#ifndef FLASHDRIVE_H
#define FLASHDRIVE_H
#include <iostream>
#include <cstdlib>
namespace cs52 {
class FlashDrive {
friend FlashDrive operator+ (FlashDrive used1 , FlashDrive used2);
friend FlashDrive operator- (FlashDrive used3, FlashDrive used4 );
public:
FlashDrive& FlashDrive::operator=(int);
FlashDrive::FlashDrive(int);
FlashDrive& operator = (const FlashDrive& usedtotal){
my_StorageUsed= usedtotal.my_StorageUsed;
return *this;
}
FlashDrive( );
FlashDrive( int capacity, int used, bool pluggedIn );
void plugIn( );
void pullOut( );
void writeData( int amount );
void eraseData( int amount );
void formatDrive( );
int getCapacity( );
void setCapacity( int amount );
int getUsed( );
void setUsed( int amount );
bool isPluggedIn( );
private:
int my_StorageCapacity; // in kilobytes
int my_StorageUsed; // in kilobytes
bool my_IsPluggedIn; // am I attached to a computer?
}extern drive1,drive2;
inline FlashDrive operator+ (FlashDrive used1, FlashDrive used2 ) {
FlashDrive plus;
plus.my_StorageUsed = (used1.getUsed()+ used2.getUsed());
return plus;
}
inline bool operator< (FlashDrive &lhs,FlashDrive &rhs ) {
return ( lhs.getUsed() < rhs.getUsed() );
}
inline bool operator> (FlashDrive &lhs,FlashDrive &rhs ) {
return ( operator <( rhs, lhs ) );
}
inline FlashDrive operator - (FlashDrive used3, FlashDrive used4 ){
FlashDrive minus;
minus.my_StorageUsed = (used3.getUsed()- used4.getUsed());
return minus;
};
}
#endif
FlashDrive.cpp
#include <iostream>
#include <cstdlib>
#include "FlashDrive.h"
namespace cs52 {
FlashDrive::FlashDrive( ) {
my_StorageCapacity = 0;
my_StorageUsed = 0;
my_IsPluggedIn = false;
}
FlashDrive::FlashDrive( int capacity, int used, bool pluggedIn ) {
my_StorageCapacity = capacity;
my_StorageUsed = used;
my_IsPluggedIn = pluggedIn;
}
void FlashDrive::plugIn( ) {
my_IsPluggedIn = true;
}
void FlashDrive::pullOut( ) {
my_IsPluggedIn = false;
}
void FlashDrive::writeData( int amount ) {
my_StorageUsed += amount;
}
void FlashDrive::eraseData( int amount ) {
my_StorageUsed -= amount;
}
void FlashDrive::formatDrive( ) {
my_StorageUsed = 0;
}
int FlashDrive::getCapacity( ) {
return( my_StorageCapacity );
}
void FlashDrive::setCapacity( int amount ) {
my_StorageCapacity = amount;
}
int FlashDrive::getUsed( ) {
return( my_StorageUsed );
}
void FlashDrive::setUsed( int amount ) {
my_StorageUsed = amount;
}
bool FlashDrive::isPluggedIn( ) {
return( my_IsPluggedIn );
}
}
Main.cpp的
#include <iostream>
#include <cstdlib>
#include "FlashDrive.h"
void main( )
{
using namespace cs52;
cs52::FlashDrive empty;
cs52::FlashDrive drive1( 10, 0, false );
cs52::FlashDrive drive2( 20, 0, false );
drive1.plugIn( );
drive1.formatDrive( );
drive1.writeData( 5 );
drive1.pullOut( );
drive2.plugIn( );
drive2.formatDrive( );
drive2.writeData( 1 );
drive2.pullOut( );
// read in a FlashDrive...
// the class designer for FlashDrive (that's you!)
// gets to decide which fields matter and should be read in
cs52::FlashDrive sample;
cin >> sample;
// print out a FlashDrive...
// the class designer for FlashDrive (that's you!)
// gets to decide which fields matter and should be printed
cout << sample << endl;
cs52::FlashDrive combined = drive1 + drive2;
cout << "this drive's filled to " << combined.getUsed( ) << endl;
cs52::FlashDrive other = combined – drive1;
cout << "the other cup's filled to " << other.getUsed( ) << endl;
if (combined > other) {
cout << "looks like combined is bigger..." << endl;
}
else {
cout << "looks like other is bigger..." << endl;
}
if (drive2 > other) {
cout << "looks like drive2 is bigger..." << endl;
}
else {
cout << "looks like other is bigger..." << endl;
}
if (drive2 < drive1) {
cout << "looks like drive2 is smaller..." << endl;
}
else {
cout << "looks like drive1 is smaller..." << endl;
}
// let's throw some exceptions...
try {
empty = empty - combined;
cout << "something not right here..." << endl;
} catch( std::logic_error ) {
// an exception should get thrown...
// so the lines of code here should
// be run, not the cout statement...
}
try {
drive2.writeData( 10000 );
cout << "something not right here..." << endl;
} catch( std::logic_error ) {
// an exception should get thrown...
// so the lines of code here should
// be run, not the cout statement...
}
try {
cs52::FlashDrive f( -1, -1, false );
cout << "something not right here..." << endl;
} catch( std::logic_error ) {
// an exception should get thrown...
// so the lines of code here should
// be run, not the cout statement...
}
}
这里有一个非常奇怪的错误消息，我正在接受
------开始构建：项目：FlashDriver，配置：调试Win32 ------ Build开始7/29/2013 4:48:43 AM。 InitializeBuildStatus：触摸“Debug FlashDriver.unsuccessfulbuild”。 ClCompile：Main.cpp c： documents and settings administrator my documents visual studio 2010 projects flashdriver flashdriver main.cpp（28）：error C2678：binary'>>'：找不到操作符， （或没有可接受的转换）c： program files microsoft visual studio 10.0 vc include istream（1053）：可能是'std :: basic_istream <_Elem，_Traits >＆std ::运算符
>（_Elem = char，_Traits = std :: char_traits）>（std :: basic_istream <_Elem，_Traits> &&，signed char *）'c： program files microsoft visual studio 10.0 vc include istream（1060） ：或'std :: basic_istream <_Elem，_Traits>＆std :: operator>（std :: basic_istream <_Elem，_Traits> &&，signed char＆）'与[_Elem = char，_Traits = std :: char_traits] c：程序文件 microsoft visual studio 10.0 vc include istream（1067）：or'std :: basic_istream <_Elem，_Traits>＆std :: operator>（std :: basic_istream <_Elem，_Traits> &&，unsigned char *）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（1074）：or'std :: basic_istream <_Elem，_Traits>＆std :: operator>（ std :: basic_istream <_Elem，_Traits> &&，unsigned char＆）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（1097）：or 'std :: basic_istream <_Elem，_Traits>＆std :: operator>（std :: basic_istream <_Elem，_Traits>＆，signed char *）'[_Elem = char，_Traits = std :: char_t （std :: basic_istream <_Elem，_Traits>＆），这是一个非常有用的工具， '_Elem，_Traits和＆std :: char_traits]与 [std :: char_traits]签署的字符＆）与C： program files microsoft visual studio 10.0 vc include istream（1111）：or'std :: basic_istream <_Elem，_Traits>＆std :: operator>（std :: basic_istream <_Elem，_Traits>＆，unsigned char *）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream （1118）：或[_Elem = char，_Traits = std :: char_traits]或'std :: basic_istream <_Elem，_Traits>＆std :: operator>（std :: basic_istream <_Elem，_Traits>＆，unsigned char＆） c： program files microsoft visual studio 10.0 vc include istream（1128）：or'std :: basic_istream <_Elem，_Traits>＆std :: operator，cs52 :: FlashDrive>（std :: basic_istream <_Elem，_Traits > &&，_ Ty＆）'[_Elem = char，_Traits = std :: char_traits，_Ty = cs52 :: FlashDrive] c： program files microsoft visual studio 10.0 vc include istream（179）：or std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator（std :: basic_istream <_Elem，Traits>＆（_ cdecl *）（std :: basic_istream < _Elem，_Traits>＆））'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（185）：or'std :: basic_istream <_Elem， _Traits>＆std :: basic_istream <_Elem，_Traits> ::运算符（std :: basic_ios <_Elem，traits>＆（_cdecl *）（std :: basic_ios <_Elem，_Traits>＆））'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（192）：or'std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator> >（std :: ios_base＆（__ cdecl *）（std :: ios_base＆））'[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream 199）或'std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator >>（std :: _ Bool＆）'与[_Elem = char，_Traits = std :: char_traits] c ： program files microsoft visual Studio 10.0 vc include istream（218）：或者'_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（253）：or'std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator> >（unsigned short＆）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（272）：or'std :: basic_istream <_Elem，_Traits >＆std :: basic_istream <_Elem，_Traits> :: operator >>（int＆）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream 298）：或[std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator >>（unsigned int＆）'与[_Elem = char，_Traits = std :: char_traits] c：程序文件 microsoft visual studio 10.0 vc include istream（316）：or'std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator >>（long ＆'）与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（334）：or'std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator >>（unsigned long＆）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（354）：或'std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，traits> :: operator >>（_ int64＆）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft Visual studio 10.0 vc include istream（373）：或'std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator >>（unsigned __int64＆）'with [_Elem = char， _Trans =＆std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（392） >>（float＆）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（411）：or'std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator >>（double＆）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（429）：or'std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator >>（long double＆）'with [_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（447）：or'std :: basic_istream <_Elem，_Traits>＆std :: basic_istream <_Elem，_Traits> :: operator >>（ void *＆）'[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include istream（466）：or'std :: basic_istream <_Elem，_Traits>＆std ::尝试匹配参数列表时，[_Elem = char，_Traits = std :: char_traits]时的:: basic_istream <_Elem，_Traits> ::运算符（std :: basic_streambuf <_Elem，_Traits> *）'（std :: istream ，cs52 :: FlashDrive）'c： documents and settings administrator my documents visual studio 2010 projects flashdriver flashdriver main.cpp（33 ）：错误C2679：二进制'<<'：找不到操作符找到类型为'cs52 :: FlashDrive'的右操作数（或者没有可接受的转换）c： program files microsoft visual studio 10.0 vc 包括 ostream（679）：可以是'std :: basic_ostream <_Elem，_Traits>＆std :: operator <<>（std :: basic_ostream <_Elem，_Traits>＆，const char *）'[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（726）：or'std :: basic_ostream <_Elem，_Traits>＆std :: operator <<>（std :: basic_ostream < _Elem，_Traits =＆，char）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（764）：or'std :: basic_ostream <_Elem ，_Traits>＆std :: operator <<>（std :: basic_ostream <_Elem，_Traits>＆，const char *）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（811）：or'std :: basic_ostream <_Elem，_Traits>＆std :: operator <<>（std :: basic_ostream <_Elem，_Traits>＆，char）' lem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（937）：or'std :: basic_ostream <_Elem，_Traits>＆std :: operator <<>（ std :: basic_ostream <_Elem，_Traits>＆，const signed char *）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（944）：或者'std :: basic_ostream <_Elem，_Traits>＆std :: operator <<>（std :: basic_ostream <_Elem，_Traits>＆，signed char）'[_Elem = char，_Traits = std :: char_traits] c：程序文件 microsoft visual studio 10.0 vc include ostream（951）：或'std :: basic_ostream <_Elem，_Traits>＆std :: operator <<>（std :: basic_ostream <_Elem，_Traits>＆，const unsigned char *）'[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（958）：or'std :: basic_ostream <_Elem，_Traits>＆std ::运算符<<>（std :: basic_ostream <_Elem，_Traits>＆，unsigned char）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 v c include ostream（968）：or'std :: basic_ostream <_Elem，_Traits>＆std :: operator <<，cs52 :: FlashDrive>（std :: basic_ostream <_Elem，_Traits> &&，_ Ty）'与[_Elem = char，_Traits = std :: char_traits，_Ty = cs52 :: FlashDrive] c： program files microsoft visual studio 10.0 vc include ostream（1085）：or'std :: basic_ostream <_Elem，_Traits>＆std： ：operator <<>（std :: basic_ostream <_Elem，_Traits>＆，const std :: error_code＆）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（186）：or std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（std :: basic_ostream <_Elem，Traits>＆（_ cdecl *）（std ）：'_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（192）：or'std :: :: basic_ostream <_Elem，_Traits>＆））' basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（std :: basic_ios <_Elem，Traits>＆（_cdecl *）（std :: basic_ios <_Elem，_Traits>＆））' [_Elem = char，_Traits = std :: ch ar_traits] c： program files microsoft visual studio 10.0 vc include ostream（199）：or'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（std： ：ios_base＆（__ cdecl *）（std :: ios_base＆））'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（206）：or 'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（std :: _ Bool）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（226）：or'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（short）'with [_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（260）：or'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator < <（unsigned short）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（280）：or'std :: basic_ostrea m <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（int）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc 使用[_Elem = char，_Traits = std :: char_traits]包含 ostream（305）：或'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（unsigned int） c： program files microsoft visual studio 10.0 vc include ostream（325）：or'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（long）'with [_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（345）：or'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem， _Traits> :: operator <<（unsigned long）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（366）：or'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，traits> :: operator <<（_ int64）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsof t视觉工作室10.0 vc include ostream（386）：or'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（unsigned __int64）'with [_Elem = char， _traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（407）：or'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（float）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（427）：or'std :: basic_ostream <_Elem，_Traits> ＆std :: basic_ostream <_Elem，_Traits> :: operator <<（double）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（447） ：或'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（long double）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（467）：or'std :: basic_ostream <_Elem，_Traits>＆std :: basic_ostream <_Elem，_Traits> :: operator <<（const void *）'与[_Elem = char，_Traits = std :: char_traits] c： program files microsoft visual studio 10.0 vc include ostream（487）：or'std :: basic_ostream <_Elem，_Traits>＆std： ：尝试匹配参数列表时，使用[_Elem = char，_Traits = std :: char_traits]时，basic_ostream <_Elem，_Traits> :: operator <<（std :: basic_streambuf <_Elem，_Traits> *）''（std :: ostream，cs52 :: FlashDrive）'c： documents and settings administrator my documents visual studio 2010 projects flashdriver flashdriver main.cpp（38）：error C2146：syntax error：missing';' 之前标识符' - 'c：文件和设置管理员我的文档 visual studio 2010 projects flashdriver flashdriver main.cpp（38）：错误C2065：' - '：未声明的标识符c： documents and settings 管理员我的文档 visual studio 2010 项目 flashdriver flashdriver main.cpp（38）：错误C2146：语法错误：缺少';' 在标识符'drive1'之前FlashDrive.cpp生成代码...
构建失败。
时间经过00：00：01.82 ==========构建：0成功，1失败，0最新，0跳过==========
您需要为class FlashDrive定义operator>>
friend std::istream& operator>>(std::istream& is, FlashDrive& fd)
{
is >> my_StorageCapacity >> my_StorageUsed >> my_IsPluggedIn;
return is;
}
类似的，你可以定义operator<<
std::ostream& operator>>(std::ostream& os, const FlashDrive& fd)
{
os << fd.getCapacity() << fd.getUsed() << fd.isPluggedIn();
return os;
}