Arrow token in a lambda expression?

Arrow token in a lambda expression?

• A. ->
• B. =>
• C. ->=
• D. <-

Answer: (A)

In lambda expressions in C++, the arrow token "->" introduces the trailing return type. It sits after the parameter list and before the function body, giving an explicit return type for the lambda, for example: auto f = [] (int x) -> double { return x * 0.5; }. If you omit the return type, the compiler tries to deduce it from the return statements inside the lambda. You’d specify a trailing return type when the return type can’t be reliably deduced or when you need to enforce a specific type, such as returning a type different from what the body would otherwise imply or when using complex expressions or templates. Note that in other languages, lambdas may use a different arrow token like "=>" (as in JavaScript or C#), so this particular syntax is specific to how C++ expresses lambda return types.

In lambda expressions in C++, the arrow token "->" introduces the trailing return type. It sits after the parameter list and before the function body, giving an explicit return type for the lambda, for example: auto f = [] (int x) -> double { return x * 0.5; }. If you omit the return type, the compiler tries to deduce it from the return statements inside the lambda. You’d specify a trailing return type when the return type can’t be reliably deduced or when you need to enforce a specific type, such as returning a type different from what the body would otherwise imply or when using complex expressions or templates. Note that in other languages, lambdas may use a different arrow token like "=>" (as in JavaScript or C#), so this particular syntax is specific to how C++ expresses lambda return types.