Is there a sane default for std::tr1::function?
I spent some time googling but didn't really find anything. I want to be able to do this:
std::tr1::function<void()> foo(SOME_DEFAULT_FUNCTION_THAT_DOES_NOTHING);
//
//Some code that could possibly assign foo
//
foo();
Otherwise I have to do this:
std::tr1开发者_开发知识库::function<void()> foo;
//
//Some code that could possibly assign foo
//
if(foo)
{
foo();
}
I realize I could just make a function that does nothing, but I am looking for some standard way of not having to deal with checking to see if the function was given a value ala the null object pattern.
void noop() { }
Could you use a boost::optional<std::tr1::function<void()> >
? That way it allows it to be set or not, and you can use an if check to see if the function has been set.
In my project I use
void noop(...) {}
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