命名空间定义和例外

Question

我在定义命名空间时遇到了一些麻烦

据我所知,我已经做好了一切

下面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...
}
}

以下是构建错误,其中大部分是冗余的

------ Build build:Project:FlashDriver,Configuration:Debug Win32 ------ Build build 7/29/2013 4:32:24 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(25):error C2065:'cin':unclared identifier c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(30):错误C2065:'cout':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(30):错误C2065:'endl':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(33):error C2065 :'cout':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(33):error C2065:'endl':unclared identifier c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(35):错误C2146:语法错误:缺少';' 在标识符之前' - 'c:\ documents和settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(35):错误C2065:' - ':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(35):错误C2146:语法错误:缺少';' 在标识符'drive1'c之前:\ documents和settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(36):错误C2065:'cout':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(36):错误C2065:'endl':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(39):错误C2065:'cout':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(39):error C2065 :'endl':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(42):error C2065:'cout':unclared identifier c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(42):error C2065:'endl':undeclared identi fier c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(46):error C2065:'cout':unclared identifier c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(46):错误C2065:'endl':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main .cpp(49):错误C2065:'cout':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(49):error C2065:'endl' :未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(53):error C2065:'cout':未声明的标识符c:\ documents and settings\administrator \我的文档\ visual studio 2010\projects\flashdriver\flashdriver\main.cpp(53):错误C2065:'endl':未声明的标识符c:\ documents和 settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(56):error C2065:'cout':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(56):错误C2065:'endl':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(62):错误C2146:语法错误:缺少';' 在标识符' - 'c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(62)之前:错误C2065:' - ':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(62):错误C2146:语法错误:缺少';' 在标识符'合并'之前c:\ documents和settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(63):错误C2065:'cout':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(63):错误C2065:'endl':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(72):错误C2065:'cout':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(72):error C2065 :'endl':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(81):error C2065:'cout':未声明的标识符c:\ documents and settings\administrator\my documents\visual studio 2010\projects\flashdriver\flashdriver\main.cpp(81):error C2065:'endl':undeclared iden tifier FlashDrive.cpp生成代码...

建立失败.

时间流逝00:00:02.50 ==========构建:0成功,1失败,0最新,0跳过==========

Answer 1

cout/cin/endl来自std名称空间,您需要使用std命名空间限定它们

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