What does an C++ operator within square brackets signify?

Question

I have a basic syntax question. I am trying to understand the meaning of an operator within square brackets when used in an assignment. E.g.

a = [&] (const std::string&) { ... };

a = [=] (const std::string& b) { ... };

Thanks,

Does this answer your question? [How does generic lambda work in C++14?](https://stackoverflow.com/questions/17233547/how-does-generic-lambda-work-in-c14) — Jason, Jul 30 '22 at 07:23

score 5 · Accepted Answer · answered May 09 '14 at 23:15

5

They distinguish between capturing variables by reference ([&]) or by value ([=]) in closures. See http://en.cppreference.com/w/cpp/language/lambda for details.

answered May 09 '14 at 23:15

thus spake a.k.

It's worth mentioning that this is a new feature in C++11; chances are not all compilers support it yet. – Keith Thompson May 10 '14 at 00:22

1 Answers1