Synopsis

(Required) A non-transient lambda shall not implicitly capture this

Enabled by default

Yes

Severity/Certainty

Medium/Medium

Full description

When class member variables are used in a lambda, this must be explicitly captured.

Coding standards

This check does not correspond to any coding standard rules.

Code examples

The following code example fails the check and will give a warning:

class C
{
  int val;
  void f() {
    // Non-compliant - val is not captured, but
    // 'this' is implicitly captured
    auto a = [&]() { return val; };
  }
};
                                  

The following code example passes the check and will not give a warning about this issue:

class C
{
  int val;
  void f() {
    // Compliant - 'this' explicitly captured
    auto a = [this]() { return val; };
  }
};