Re: Idea for more delegations in <algorithm>

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

Paolo Carlini <pcarlini@suse.de> writes:

| Chris Jefferson wrote:
| 
| > | Or, for some reason, we have troubles with this too? :(
| >
| > Unless I'm going mad (possible), default parameters are inserted and
| > passed by the compiler (at least on x86), so this will in fact be worse,
| > because that "0" will always be created and passed by the compiler
| > (because it might be needed for all it knows) whereas the empty classes
| > might eventually be optimised away with compiler improvements.
| 
| I see, I was afraid that something like that could happen, in
| principle (have never looked myself to the actual way defaults are
| compiled)

There is always a value passed to the function -- when none is
lexically specified in the source code, the compiler uses the default
value. 

The situation is slightly different for empty classes: we and the
compiler know that a value of that type is insignificant.  So, it
could be safely not loaded into the argument list.

For the enable-if stuff, only we (and not the compiler) know that the
default is just a hackery artefact -- except when the function is of
course inline and inlined.

-- Gaby