From: David Greene (greened_at_[hidden])
Date: 2006-01-11 12:56:00
I'm debugging some even nastier lambda compiler error messages
(not sure if I can reduce to a testcase but I'll try). In the
course of figuring this out, I relized that I need to understand
the similarities and/or differences between bind operations and
->* in a lambda context.
What is the difference between these two:
class Class {
public:
int member_func(void);
};
bind(&Class::member_func, _1) == 1
(_1 ->* &Class::member_func) == 1
used in the context of
std::find_if(seq.being(), seq.end(), <lambda-func>);
Does the second construct make sense in this case? I don't think it
does because member_func takes no arguments. Because the ->*
expression must be followed immediately by an argument list, there
is no way to delay the substitution of the object on which to
call member_func. This, I believe, it what bind is for.
That is, ->* only delays application of n-1 arguments, where n
is the total arity of the function (including the hidden "this"
parameter).
Bind is able to delay application of all n arguments.
Is this analysis correct?
-Dave