在我的main.cpp中:
using namespace std;
#include <cstdlib>
#include <iostream>
#include <set>
#include <string>
#include <cstring>
#include <sstream>
#include <algorithm>
class findme
{
public:
bool operator()(const std::string& s) {
return s == "tom";
}
};
int main(int argc, char *argv[])
{
set<string> myset;
myset.insert("tom");
myset.insert("jerry");
cout << myset.size();
set<string>::iterator it;
if (find_if(myset.begin(), myset.end(), findme())) {
cout << "found tom \n";
}
return EXIT_SUCCESS;
}
当我编译程序时,它出错了:
Could not convert std::find_if [with _InputIterator = std::_Rb_tree_const_iterator<std::string>, _Predicate = findme]((&myset)->std::set<_Key, _Compare, _Alloc>::begin [with _Key = std::string, _Compare = std::less<std::string>, _Alloc = std::allocator<std::string>](), (&myset)->std::set<_Key, _Compare, _Alloc>::end [with _Key = std::string, _Compare = std::less<std::string>, _Alloc = std::allocator<std::string>](), (findme(), findme()))' to 'bool'
anyboy可以告诉我哪里错了吗?谢谢
答案 0 :(得分:11)
std::find_if
返回找到的元素的迭代器(如果没有元素与谓词匹配,则返回一个结尾):
std::set<std::string>::iterator it =
std::find_if(myset.begin(), myset.end(), findme());
if (it != myset.end())
{
// etc.