【1】std::remove_if
今天突然有同事问下面这段代码应如何理解。
源码如下：
void GStiffenerBlockRepoDefaultImpl::destory(int id) noexcept
{
m_stiffeners.erase(std::remove_if(std::begin(m_stiffeners), std::end(m_stiffeners), [&](auto s)->bool {
return s.id == id;
}), std::end(m_stiffeners));
}
【2】应用示例
用代码说话，比讲解更容易理解。请看如下示例与运行结果：
（1）示例程序
1 #include <iostream>
2 #include <string>
3 #include <vector>
4 #include <algorithm>
5 using namespace std;
6
7 int main()
8 {
9 vector<string> srcStr = { "apple", "banana", "key", "cat", "dog", "orange", "banana", "pig", "dog", "monkey" };
10
11 auto printSrc = [&]() {
12 int index = 0;
13 for (auto& item : srcStr)
14 {
15 cout << (index++) << "|" << item << " ";
16 }
17 };
18
19 cout << "*************************************************" << endl;
20 cout << "the original element of vector size :: " << srcStr.size() << endl;
21 cout << "the original element of vector :: " << endl;
22 printSrc();
23 cout << endl << "*************************************************" << endl;
24
25 cout << endl << "+++++++++++++++++++++++++++++++++++++++++++++++++" << endl;
26 auto find_str = "banana";
27 auto sd = remove_if(srcStr.begin(), srcStr.end(), [&](string element) { return element == find_str; });
28 cout << "after remove banana size :: " << srcStr.size() << endl;
29 cout << "after remove banana :: " << endl;
30 printSrc();
31
32 int index = 0;
33 vector<string>::iterator iter = sd;
34 cout << endl << "before erase banana, prepare to erase data :: " << endl;
35 for (; iter != srcStr.end(); ++iter)
36 {
37 cout << (index++) << "|" << *iter << " ";
38 }
39
40 srcStr.erase(sd, srcStr.end());
41 cout << endl << "after erase banana size :: " << srcStr.size() << endl;
42 cout << "after erase banana data :: " << endl;
43 printSrc();
44 cout << endl << "+++++++++++++++++++++++++++++++++++++++++++++++++" << endl;
45
46 cout << endl << "=================================================" << endl;
47 find_str = "dog";
48 srcStr.erase(remove_if(srcStr.begin(), srcStr.end(),
49 [&](string element) { return element == find_str; }),
50 srcStr.end());
51
52 cout << "after erase dog size :: " << srcStr.size() << endl;
53 cout << "after erase dog data :: " << endl;
54 printSrc();
55 cout << endl << "=================================================" << endl;
56
57 return 0;
58 }
（2）运行结果
【3】总结
（1）
（2）