C++ Lambda expressions


A lambda can only have a trailing return type; the leading return type syntax is not applicable to lambdas. Note that in many cases it is not necessary to specify a return type for a lambda at all.

struct Base {};
struct Derived1 : Base {};
struct Derived2 : Base {};
auto lambda = [](bool b) -> Base* { if (b) return new Derived1; else return new Derived2; };
// ill-formed: auto lambda = Base* [](bool b) { ... };