Overloading Lazy Vs. Non-Lazy

[Steven Schveighoffer]

On Thu, 12 Aug 2010 02:00:00 -0400, Brad Roberts <braddr at puremagic.com>  
wrote:

> On 8/11/2010 6:19 AM, dsimcha wrote:
>> An issue that's come up here several times before is that enforce()
>> effectively disables inlining of the function it's used in.  From  
>> reading some
>> disassemblies, the reason seems to be because of all the ASM code that's
>> required for lazy parameters.  I wonder if either of the following is  
>> feasible:
>>
>> 1.  When a function takes a lazy parameter, the compiler automatically
>> generates two versions under the hood:  One that actually takes a  
>> non-lazy
>> parameter and is used when the value is known at compile time and  
>> another that
>> works like current lazy functions.  The only problem here is that this  
>> might
>> create issues when using function pointers/delegates.
>>
>> 2.  Allow overloading of lazy and non-lazy functions, with the rule  
>> that the
>> lazy version gets called whenever the value must be computed at runtime  
>> and
>> the non-lazy version gets called if the value is statically known and  
>> thus
>> there's no evaluation to speak of.
>
> It's the throw that blocks inlining right now.  Lazy might also disable  
> inlining
> too, I haven't looked for that case.  Either way, that's purely a  
> quality of
> implementation issue.  I don't think it'd be a good idea to bend the  
> library all
> that much to work around that kind of limitation.  It's something that  
> will get
> better as time permits.

Well, there's something to be said about preventing the bloated generation  
of code that accompanies lazy.

But throwing preventing inlining is a bad one, that should be fixed.

-Steve