值捕获、引用捕获

#include <iostream>
using namespace std;
int main(){
    size_t v1=42;
    auto f=[v1]{return v1;};
    auto f2=[&v1]{return v1;};
    v1=0;
    auto j=f();
    auto j1=f2();
    cout<<j<<endl;
    cout<<j1<<endl;
}

输出

42
0

隐式捕获

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;

void biggies(vector<string> &words,vector<string>::size_type sz,ostream &os=cout){
    auto wc=find_if(words.begin(),words.end(),[=](const string &s){return s.size()>=sz;});
    cout<<*wc<<endl;
}
int main(){
    vector<string> v={"abc","bdf","caaaaa"};
    biggies(v,4);
}

隐式捕获sz
输出caaaaa