class My_class {
    int x = 0;
    // ...

void f() {
    int i = 0;
    // ...

    auto lambda = [=]{ use(i, x); };   // BAD: "looks like" copy/value capture
    // [&] has identical semantics and copies the this pointer under the current rules
    // [=,this] and [&,this] are not much better, and confusing

    x = 42;
    lambda(); // calls use(42);
    x = 43;
    lambda(); // calls use(43);

    // ...

    auto lambda2 = [i, this]{ use(i, x); }; // ok, most explicit and least confusing

    // ...
}

auto lambda = [=]{ use(i, x); };

auto lambda2 = [i, this]{ use(i, x); };

#include<iostream>
using namespace std;

class My_class {
public:
    int x = 0;
    // ...

    void f() {
        int i = 0;
        // ...

        auto lambda = [=]{ cout<<i<<x<<endl; };   // BAD: "looks like" copy/value capture
        // [&] has identical semantics and copies the this pointer under the current rules
        // [=,this] and [&,this] are not much better, and confusing

        x = 42;
        lambda(); // calls use(42);
        x = 43;
        lambda(); // calls use(43);

        // ...

        auto lambda2 = [i, this]{ cout<<i<<x<<endl; }; // ok, most explicit and least confusing

        lambda2();
    }
};

int main()
    {
        My_class val;
        val.f();
    }

042
043
043
Program ended with exit code: 0