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From: Sean Hunt <rideau3@gmail.com>
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Subject: Re: How many parameters in T({x, y, z}) ?
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On Oct 31, 12:58 am, Scott Meyers <use...@aristeia.com> wrote:
> Is this a bug in my understanding or a bug in gcc's implementation?
>
> Thanks,
>
> Scott

When you call "Widget w({ 10, 20, 30 })", the compiler sees two
candidates for the constructor - one taking const Widget&, and one
taking three ints. Neither of those is a direct match, but it is
possible to list-initialize a temporary of type Widget using the
triple-int constructor, and then call the copy constructor. This
behavior seems odd for constructors, but it makes sense in the
following scenario:

void foo (int, int, int);
void foo (const Widget&);

int main() {
   foo({10, 20, 30});
}

Would you really expect that call to foo to call the first declaration
of foo?

If you wish to initialize w directly from an initializer-list of three ints, 
you should declare it as "Widget w {10, 20, 30};", which, as I understand it, 
is the initialization syntax that will Do the Right Thing  in nearly every 
scenario.

Sean Hunt


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