(Params){ FunctionBody; } Rule: ref|opt ParameterWithMemberAttributes FunctionLiteralBody
https://dlang.org/spec/expression.html#function_literals void function() Is a type https://dlang.org/spec/type.html#delegates () => {} Is actually: () => Expression Rule: ref|opt ParameterWithMemberAttributes => AssignExpression https://dlang.org/spec/expression.html#lambdas