Re: [Boost-build] Sun toolset

From: Caleb Epstein (caleb.epstein_at_[hidden])
Date: 2006-12-02 20:32:25

On 12/2/06, K. Noel Belcourt <kbelco_at_[hidden]> wrote:
>  From Sun's CC manpage,
>
>                 [no%]tmplife   (Standard mode only) [Do not] Clean
>                                up the temporary objects that are
>                                created by an expression at the end
>                                of the full expression, as defined
>                                in the ANSI/ISO C++ Standard.
>                                (When -features=no%tmplife is in
>                                effect, most temporary objects are
>                                cleaned up at the end of their
>                                block.) The default is no%tmplife.
>
> Which I read to mean that -features=tmplife leaves temporary files
> scattered around.

Nothing of the sort.  It has to do with the lifetime of temporaries
created in expressions like:

   void foo (const std::string& arg) { ... }

   void func () {
      foo ("bar"); // [1]
      // more stuff...
  } // [2]

With Sun CC's default (-no%tmplife), the unnamed temporary std::string
created for the call to foo would not be destroyed until the enclosing
scope exits ([2] above).  A conforming compiler (and Sun CC with
-tmplife) will destroy the temporary at [1].  In the case of
std::string this side-effect is harmless, but for more "interesting"
types the default behavior could be disastrous.

-- 
Caleb Epstein