Familiar template syntax for generic lambdas

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The result of a lambda expression is not a function; it is a function object. That is, it is a class type that has an operator() overload on it. So this:

auto f = []<typename T>( T t ) {};

Is equivalent to this:

struct unnamed
{
  template<typename T>
  void operator()(T t) {}
};

auto f = unnamed{};

If you want to explicitly provide template arguments to a lambda function, you have to call operator() explicitly: f.operator()<template arguments>(parameters);.

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