我确定我在这里做了一些愚蠢的事情,但我看不到它。为什么以下不编译?
#include <algorithm>
#include <memory>
#include <vector>
#include <string>
// A class to play with. Encapsulates a name.
class StringClass
{
public:
StringClass(std::string const & name) : MyName(name)
{
}
std::string const & Name() const
{
return MyName;
}
private:
std::string MyName;
};
// The set of instances of "StringClass".
std::vector<std::shared_ptr<StringClass>> MyInstances;
// Function returns "true" if a class with the given name exists in the collection.
bool Exists(std::string const & name)
{
auto i = std::find(MyInstances.begin(), MyInstances.end(), [&](std::shared_ptr<StringClass> const & instance) {
return instance->Name() == name;
});
return i != MyInstances.end();
}
我已经将 shared_ptr 的向量添加到了一个类中。该类有一个 Name() 属性。我要做的就是迭代向量以查找具有给定名称的类的实例。但是,它不会编译:(。
错误是:
1>ClCompile: 1> test.cpp 1>c:\program files (x86)\microsoft visual studio 10.0\vc\include\algorithm(41): error C2679: binary '==' : no operator found which take a right - 'const 匿名命名空间'::)' 1> 类型的手动操作数 1> [ 1> _Ty=StringClass 1> ] 1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\algorithm (74) : 参见对函数模板实例化 '_InIt std::_Find*, anonymous-namespace':: &)' 的引用 1> 使用 1> [ 1> _InIt=std::tr1::shared_ptr *, 1> _Ty=StringClass 1> ] 1> c:\svn\trunk\test\test\test.cpp(55) : 参见函数模板实例化 '_InIt std::find,
anonymous-namespace'::<lambda0>' (or there is no acceptable conversion) 1> could be 'built-in C++ operator==(std::_Bool_type, std::_Bool_type)' 1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\exception(470): or 'bool std::operator ==(const std::_Exception_ptr &,const std::_Exception_ptr &)' 1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\exception(475): or 'bool std::operator ==(std::_Null_type,const std::_Exception_ptr &)' 1>
c:\program files (x86)\microsoft visual studio 10.0\vc\include\exception(481): or 'bool std::operator ==(const std::_Exception_ptr &,std::_Null_type)' 1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\system_error(408): or
'bool std::operator ==(const std::error_code &,const std::error_condition &)' 1> c:\program files (x86)\microsoft visual studio 10.0\vc\include\system_error(416): or 'bool std::operator ==(const std::error_condition &,const std::error_code &)' 1> while trying to match the argument list '(std::tr1::shared_ptr<_Ty>, constanonymous-namespace'::<lambda0>>(_InIt,_InIt,const
anonymous-namespace'::<lambda0>>(_InIt,_InIt,const _Ty &)' being compiled 1> with 1> [ 1> _InIt=std::_Vector_iterator<std::_Vector_val<std::tr1::shared_ptr<StringClass>,std::allocator<std::tr1::shared_ptr<StringClass>>>>, 1>
匿名命名空间':: 1> ] 1> stdafx.cpp 1> 生成代码... 1> 1> 构建失败。1> 1> 经过时间 00:00:00.87 ========== 构建:0 成功,1 失败,0 最新,0 跳过 ==========
_Myvec=std::_Vector_val<std::tr1::shared_ptr<StringClass>,std::allocator<std::tr1::shared_ptr<StringClass>>>, 1> _Ty=