我正在学习通过游戏编程开始C ++
在书中我有这个例子：
#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;
int main (){
string word1 = "Game";
string word2("Over");
string word3(3, '!');
string phrase= word1 + word2 + word3;
string phrase= word1 + "" + word2 + word3;
cout<< " The phrase is: " << phrase << "\n \n";
cout<< " The phrase has " << phrase.size() << "on it! \n\n";
cout<< " The character at position 0 is " << phrase[0] << "on it! \n\n";
cout<< "Changing the character at position 0 \n\n";
phrase[0] = 'V';
cout << "The phrase now is " << phrase << "\n\n";
for( unsigned int i=0; i < phrase.size() ; i++){
cout << " Character at position "<< i << "is : " << phrase[i] << "\n" ;
}
cout << "The word 'Over' begin at " << phrase.find("Over") << endl;
if (phrase.find("eggplant")==string::npos)
{
cout<<"'Eggplant' is not in the phrase"<<endl;
}
phrase.erase(4,5);
cout<<"phrase now is" << phrase << endl;
phrase.erase();
if(phrase.empty())
{
cout << "phrase is empty" << endl;
}
getchar();
}
当我尝试运行代码时，调试会给我回复：
1>------ Build started: Project: GameTestExample, Configuration: Debug Win32 ------
1> gameover.cpp
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(14): error C2784: 'std::_String_iterator<_Mystr> std::operator +(_String_iterator<_Mystr>::difference_type,std::_String_iterator<_Mystr>)' : could not deduce template argument for 'std::_String_iterator<_Mystr>' from 'std::string'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xstring(420) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xstring(420) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xstring(420) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xstring(420) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(14): error C2784: 'std::_String_const_iterator<_Mystr> std::operator +(_String_const_iterator<_Mystr>::difference_type,std::_String_const_iterator<_Mystr>)' : could not deduce template argument for 'std::_String_const_iterator<_Mystr>' from 'std::string'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xstring(288) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xstring(288) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xstring(288) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xstring(288) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(14): error C2784: 'std::move_iterator<_RanIt> std::operator +(_Diff,const std::move_iterator<_RanIt> &)' : could not deduce template argument for 'const std::move_iterator<_RanIt> &' from 'std::string'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1947) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1947) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1947) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1947) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(14): error C2784: 'std::_Array_iterator<_Ty,_Size> std::operator +(_Array_iterator<_Ty,_Size>::difference_type,std::_Array_iterator<_Ty,_Size>)' : could not deduce template argument for 'std::_Array_iterator<_Ty,_Size>' from 'std::string'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1801) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1801) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1801) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1801) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(14): error C2784: 'std::_Array_const_iterator<_Ty,_Size> std::operator +(_Array_const_iterator<_Ty,_Size>::difference_type,std::_Array_const_iterator<_Ty,_Size>)' : could not deduce template argument for 'std::_Array_const_iterator<_Ty,_Size>' from 'std::string'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1662) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1662) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1662) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1662) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(14): error C2784: 'std::reverse_iterator<_RanIt> std::operator +(_Diff,const std::reverse_iterator<_RanIt> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'std::string'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1226) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1226) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1226) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1226) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(14): error C2784: 'std::_Revranit<_RanIt,_Base> std::operator +(_Diff,const std::_Revranit<_RanIt,_Base> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'std::string'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1031) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1031) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1031) : see declaration of 'std::operator +'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1031) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(14): error C2676: binary '+' : 'std::string' does not define this operator or a conversion to a type acceptable to the predefined operator
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(15): error C2374: 'phrase' : redefinition; multiple initialization
1> c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(14) : see declaration of 'phrase'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(15): error C2784: 'std::_String_iterator<_Mystr> std::operator +(_String_iterator<_Mystr>::difference_type,std::_String_iterator<_Mystr>)' : could not deduce template argument for 'std::_String_iterator<_Mystr>' from 'const char [1]'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xstring(420) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(15): error C2784: 'std::_String_const_iterator<_Mystr> std::operator +(_String_const_iterator<_Mystr>::difference_type,std::_String_const_iterator<_Mystr>)' : could not deduce template argument for 'std::_String_const_iterator<_Mystr>' from 'const char [1]'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xstring(288) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(15): error C2784: 'std::move_iterator<_RanIt> std::operator +(_Diff,const std::move_iterator<_RanIt> &)' : could not deduce template argument for 'const std::move_iterator<_RanIt> &' from 'const char [1]'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1947) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(15): error C2784: 'std::_Array_iterator<_Ty,_Size> std::operator +(_Array_iterator<_Ty,_Size>::difference_type,std::_Array_iterator<_Ty,_Size>)' : could not deduce template argument for 'std::_Array_iterator<_Ty,_Size>' from 'const char [1]'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1801) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(15): error C2784: 'std::_Array_const_iterator<_Ty,_Size> std::operator +(_Array_const_iterator<_Ty,_Size>::difference_type,std::_Array_const_iterator<_Ty,_Size>)' : could not deduce template argument for 'std::_Array_const_iterator<_Ty,_Size>' from 'const char [1]'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1662) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(15): error C2784: 'std::reverse_iterator<_RanIt> std::operator +(_Diff,const std::reverse_iterator<_RanIt> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const char [1]'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1226) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(15): error C2784: 'std::_Revranit<_RanIt,_Base> std::operator +(_Diff,const std::_Revranit<_RanIt,_Base> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const char [1]'
1> c:\program files (x86)\microsoft visual studio 11.0\vc\include\xutility(1031) : see declaration of 'std::operator +'
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(15): error C2676: binary '+' : 'std::string' does not define this operator or a conversion to a type acceptable to the predefined operator
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(17): error C2088: '<<' : illegal for class
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(20): error C2088: '[' : illegal for class
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(23): error C2088: '[' : illegal for class
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(24): error C2088: '<<' : illegal for class
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(28): error C2088: '[' : illegal for class
1>c:\users\victor\documents\visual studio 2012\projects\gametestexample\gametestexample\gameover.cpp(37): error C2088: '<<' : illegal for class
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
所以，我的观点是，究竟发生了什么？无法意识到这是否是“旧语法”之类的问题，我之前从未见过这样的问题或代码是错的（我不能相信，没有人会像书中那样失败）< / p>
我正在使用Microsoft Visual Studio Premium 20112作为开发环境
答案 0 :(得分：3)
也使用#include <string>。