C++17 STL Cookbook

Capture list

Specifies if and what we capture. There are several forms to do so. There are two lazy variants:

• If we write [=] () {...}, we capture every variable the closure references from outside by value, which means that the values are copied
• Writing [&] () {...} means that everything the closure references outside is only captured by reference, which does not lead to a copy.

Of course, we can set the capturing settings for every variable individually. Writing [a, &b] () {...} means, that we capture the variable a by value, and b by reference. This is more typing work, but it's generally safer to be that verbose because we cannot accidentally capture something we don't want to capture from outside.

In the recipe, we defined a lambda ...