std::inserter无法工作。

Question

我正在编写一段代码，其中一个文件使用了set_intersection函数，而这个函数的最后一个参数应该是插入器。但是当我编译代码时，出现以下错误：

error C2039: 'inserter' : is not a member of 'std'
error C2873: 'inserter' : symbol cannot be used in a using-declaration
error C3861: 'inserter': identifier not found

以下是使用set_intersection函数的文件中的代码

#include "Query.h"
#include "TextQuery.h"
#include <set>
#include <algorithm>
#include <iostream>

using std::set;
using std::ostream;
using std::inserter; 
using std::set_intersection;

// returns intersection of its operands' result sets
set<TextQuery::line_no>
AndQuery::eval(const TextQuery& file) const
{
    // virtual calls through the Query handle to get result sets for the operands
    set<line_no> left = lhs.eval(file), 
                 right = rhs.eval(file);

    set<line_no> ret_lines;  // destination to hold results 

    // writes intersection of two ranges to a destination iterator
    // destination iterator in this call adds elements to ret
    set_intersection(left.begin(), left.end(), 
                  right.begin(), right.end(),
                  inserter(ret_lines, ret_lines.begin()));
    return ret_lines;
}

- user1232138

Answer 1

您需要包含 <iterator> 头文件。

- Cătălin Pitiș

Answer 2

你忘记了 #include <iterator>。

- Jon