Function scope arguments

[Artur Skawina]

On 01/15/13 12:48, deadalnix wrote:
> On Tuesday, 15 January 2013 at 10:58:17 UTC, Artur Skawina wrote:
>> Different problem - lifetime. One approach would be to disallow escaping
>> them (which in this case includes returning them) unless the compiler is
>> able to do the right - ie the body of the function is available. Somewhat
>> unorthodox, but could work. (The problem are not the trivial cases; it's the
>> ones where the compiler has no idea which ref is escaped/returned at runtime)
>>
> 
> The compiler should assume they may escape unless scope is specified.

This is about /avoiding/ "hidden" heap allocations as much as possible. Having
functions with 'ref' and 'auto-ref' args always trigger them is not ideal.

'lazy' args are already problematic enough. (there's currently no way to mark
them as non-escaping, the compiler has to assume that the do -> the result is
that they /always/ cause heap allocations and you have to use explicit scoped
delegates instead, losing the syntax advantages)

artur