lambda17.cpp

int a = 1, b = 2;

[&]		// capture local variables as &a, &b
{
	a = 3;	// &a = 3
	b = 4; 
}();		// instant execution

[=]		// capture local variables const a, const b
{
	a = 1;				// COMPILE ERROR
	const_cast<int &>(b) = 1;	// changes copied another b
}();
std::cout << a << ' ' << b << std::endl;// 3 4

int q = 1;
[q]() mutable { q = 2; }();		// changes copied another q
std::cout << q << std::endl;		// 1

[&x = q]() { x = 5; }();		// update original q through reference x
std::cout << q << std::endl;		// 5

auto cfn = []() constexpr -> int { return 'A'; };
std::cout << cfn() << std::endl; // 65