Re: Why don't Function Lambdas Cast to Delegate?
On Monday, 21 November 2016 at 16:24:38 UTC, Q. Schroll wrote: Why don't lambdas cast to a delegate if they are of type R function(Args)? I don't see any reason to that; a lambda should be a delegate type by default, and a function only as a special guarantee/optimization. It just makes them cumbersome to use with toDelegate. Probably there is a good reason why R function(Args) does not implicitly cast to R delegate(Args); I can imagine something internally (memory layout etc.) causes that. I'd just like to know. A delegate has the hidden context pointer as parameter in addition to the 'visible' parameters. That causes functions and delegates with the same declared params to look different on the ABI level.
Re: Why don't Function Lambdas Cast to Delegate?
On 11/21/16 11:24 AM, Q. Schroll wrote: Why don't lambdas cast to a delegate if they are of type R function(Args)? I don't see any reason to that; a lambda should be a delegate type by default, and a function only as a special guarantee/optimization. It just makes them cumbersome to use with toDelegate. Probably there is a good reason why R function(Args) does not implicitly cast to R delegate(Args); I can imagine something internally (memory layout etc.) causes that. I'd just like to know. The ABI for function calls is different than the ABI for delegate calls. I believe this is a necessary limitation due to ABIs on some platforms, but I'm not 100% sure. It could just be a legacy issue. -Steve
Why don't Function Lambdas Cast to Delegate?
Why don't lambdas cast to a delegate if they are of type R function(Args)? I don't see any reason to that; a lambda should be a delegate type by default, and a function only as a special guarantee/optimization. It just makes them cumbersome to use with toDelegate. Probably there is a good reason why R function(Args) does not implicitly cast to R delegate(Args); I can imagine something internally (memory layout etc.) causes that. I'd just like to know.
