Re: [boost] [mpl] conditional expressions

From: David Abrahams (dave_at_[hidden])
Date: 2003-01-28 14:56:19

"Rozental, Gennadiy" <gennadiy.rozental_at_[hidden]> writes:

> Hi,
>
> Is there neat way with MPL to implement conditional expessions without
> introducing aditional structures. For example:
>
> template<typename Container>
> void
> foo( Container& c ) 
> {
> // pseudo code
>    [if ( c is reservable , i.e. has method reserve )
>        c.reserve( 100 );
>    ]
>    ...    
> }
>
> Gennadiy.

If I understand the question correctly (not sure I do because it's
vaguely worded), the answer is no.  C++ compilation in general is not
lazy, so you can't defer the call to reserve() unless you go through a
level of template indirection.

-- 
                       David Abrahams
   dave_at_[hidden] * http://www.boost-consulting.com
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