using set.count() return

[Gary Wessle]

Hi

can I use
if( set.count(key) ) // element exists
{
// do something.
}
else if( !set.count(key) ) // it does not exist
{
// so something else.
}
http://www.cppreference.com/cppset/count.html
count() returns the number of occurrences of key in the set.
size_type count( const key_type& key );

well, if set is like a map with values are them selves the keys, and
the map holds unique keys, then count will always return 1 if the key
exist and 0 if it does not.

what am I missing?

thanks

[Marcus Kwok]

Gary Wessle <ph****@yahoo.comwrote:

can I use
if( set.count(key) ) // element exists
{
// do something.
}
else if( !set.count(key) ) // it does not exist
{
// so something else.
}

I see no reason why not, though set.find(key) == set.end() (or != as
appropriate) may indicate your intentions more clearly.

http://www.cppreference.com/cppset/count.html
count() returns the number of occurrences of key in the set.
size_type count( const key_type& key );

well, if set is like a map with values are them selves the keys, and
the map holds unique keys, then count will always return 1 if the key
exist and 0 if it does not.

what am I missing?

In addition to std::set, there is std::multiset, in which case
set.count() may return a number greater than 1.

--
Marcus Kwok
Replace 'invalid' with 'net' to reply