命名空間定義與異常

Question

我在定義名稱空間時遇到了一些麻煩

據我所知，我做對了所有事情

下面是我的代碼和構建輸出

閃存盤

#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

#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...
}
}

這是構建錯誤，其中大多數是多余的

------構建開始：項目：FlashDriver，配置：調試Win32 ------構建開始於2013年7月29日4:32:24 AM。 InitializeBuildStatus：觸摸“ Debug \\ FlashDriver.unsuccessfulbuild”。 ClCompile：Main.cpp c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（25）：error C2065：'cin'：未聲明的標識符c：\\ documents和settings \\管理員\\我的文檔\\ Visual Studio 2010 \\項目\\ FlashDriver \\ FlashDriver \\ Main.cpp（30）：錯誤C2065：'cout'：未聲明的標識符c：\\文檔和設置\\管理員\\我的文檔\\ Visual Studio 2010 \\ Projects \\ FlashDriver \\\\ flashdriver \\ main.cpp（30）：錯誤C2065：'endl'：未聲明的標識符c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（33）：錯誤C2065 ：'cout'：未聲明的標識符c：\\ documents和settings \\ administrator \\我的文檔\\ Visual Studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（33）：錯誤C2065：'endl'：未聲明的標識符c：\\ documents和設置\\管理員\\我的文檔\\ Visual Studio 2010 \\項目\\ flashdriver \\ flashdriver \\ main.cpp（35）：錯誤C2146：語法錯誤：缺少';' 標識符'–'c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（35）之前：錯誤C2065：'–'：未聲明的標識符c：\\ documents和settings \\管理員\\我的文檔\\ Visual Studio 2010 \\項目\\ flashdriver \\ flashdriver \\ main.cpp（35）：錯誤C2146：語法錯誤：缺少';' 標識符'drive1'之前c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（36）：error C2065：'cout'：未聲明的標識符c：\\ documents和settings \\管理員\\我的文檔\\ Visual Studio 2010 \\項目\\ FlashDriver \\ FlashDriver \\ Main.cpp（36）：錯誤C2065：'endl'：未聲明的標識符c：\\文檔和設置\\管理員\\我的文檔\\ Visual Studio 2010 \\ Projects \\ FlashDriver \\ flashdriver \\ main.cpp（39）：錯誤C2065：'cout'：未聲明的標識符c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（39）：錯誤C2065 ：'endl'：未聲明的標識符c：\\ documents和settings \\ administrator \\我的文檔\\ Visual Studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（42）：錯誤C2065：'cout'：未聲明的標識符c：\\ documents和設置\\管理員\\我的文檔\\ Visual Studio 2010 \\項目\\ FlashDriver \\ FlashDriver \\ Main.cpp（42）：錯誤C2065：'endl'：未聲明的identi 正確的c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（46）：錯誤C2065：'cout'：未聲明的標識符c：\\ documents和settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（46）：錯誤C2065：“ endl”：未聲明的標識符c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main .cpp（49）：錯誤C2065：'cout'：未聲明的標識符c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（49）：錯誤C2065：'endl' ：未聲明的標識符c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（53）：錯誤C2065：'cout'：未聲明的標識符c：\\ documents和settings \\ administrator \\我的文檔\\ Visual Studio 2010 \\項目\\ FlashDriver \\ FlashDriver \\ Main.cpp（53）：錯誤C2065：“ endl”：未聲明的標識符c：\\ documents和 設置\\管理員\\我的文檔\\ Visual Studio 2010 \\項目\\ FlashDriver \\ FlashDriver \\ Main.cpp（56）：錯誤C2065：'cout'：未聲明的標識符c：\\文檔和設置\\管理員\\我的文檔\\ Visual Studio 2010 \\ Projects \\\\ flashdriver \\ flashdriver \\ main.cpp（56）：錯誤C2065：'endl'：未聲明的標識符c：\\ documents和settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（62）：錯誤C2146：語法錯誤：缺少';' 標識符'–'c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（62）之前：錯誤C2065：'–'：未聲明的標識符c：\\ documents和settings \\管理員\\我的文檔\\ Visual Studio 2010 \\項目\\ FlashDriver \\ FlashDriver \\ Main.cpp（62）：錯誤C2146：語法錯誤：缺少';' 標識符'combined'之前c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（63）：error C2065：'cout'：未聲明的標識符c：\\ documents和settings \\管理員\\我的文檔\\ Visual Studio 2010 \\項目\\ FlashDriver \\ FlashDriver \\ Main.cpp（63）：錯誤C2065：'endl'：未聲明的標識符c：\\文檔和設置\\管理員\\我的文檔\\ Visual Studio 2010 \\ Projects \\ FlashDriver \\ flashdriver \\ main.cpp（72）：錯誤C2065：'cout'：未聲明的標識符c：\\ documents and settings \\ administrator \\ mydocuments \\ visual studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（72）：錯誤C2065 ：'endl'：未聲明的標識符c：\\ documents and settings \\ administrator \\我的文檔\\ Visual Studio 2010 \\ projects \\ flashdriver \\ flashdriver \\ main.cpp（81）：錯誤C2065：'cout'：未聲明的標識符c：\\ documents和設置\\管理員\\我的文檔\\ Visual Studio 2010 \\項目\\ FlashDriver \\ FlashDriver \\ Main.cpp（81）：錯誤C2065：'endl'：未聲明的Iden tifier FlashDrive.cpp生成代碼...

建立失敗。

經過的時間00：00：02.50 ==========構建：0成功，1失敗，0最新，跳過0 ==========

Answer 1

cout/cin/endl從STD命名空間，則需要使用std名字空間要符合他們

std::cout
std::cin
std::endl