Re: [Boost-users] [Boost.Function] (too) loosly treated argument types

From: Thorsten Ottosen (thorsten.ottosen_at_[hidden])
Date: 2007-01-02 12:09:26

Doug Gregor wrote:
> On Dec 27, 2006, at 5:00 PM, Slawomir Lisznianski wrote:
> 
>>Given example below, is there any way to enforce parameter type  
>>strictness?
>>[snip]
>>typedef function1<void, int &> signature;
>>
>>void fn1(int v) // notice arg by-value (say, user typo)
>>{
>>   // here, assignments to `v' are lost after
>>   // return
>>}
>>[snip]
>>   // I want this to fail at compile-time...
>>   signature f1 = fn1;
>>[snip]
>>On my compiler (g++ (GCC) 4.0.2 20051125) everything compiles fine but
>>ideally, I'd like to fail the first case.
> 
> 
> I don't know of any way to enforce parameter type strictness. It  
> would probably require looking into the actual function object that  
> the user has passed, then using some kind of metaprogram to determine  
> if the parameters are strict enough.

I think the signature can to some extend be respected by passing
something line a boost::reference_wrapper<int> instead of an int&.

-Thorsten