std::flat_set<Key,Compare,KeyContainer>:: contains
From cppreference.net
|
bool
contains
(
const
Key
&
key
)
const
;
|
(1) |
(since C++23)
(constexpr since C++26) |
|
template
<
class
K
>
bool contains ( const K & x ) const ; |
(2) |
(since C++23)
(constexpr since C++26) |
1)
Checks if there is an element with key equivalent to
key
in the container.
2)
Checks if there is an element with key that compares equivalent to
x
.
This overload participates in overload resolution only if
Compare
is
transparent
. It allows calling this function without constructing an instance of
Key
.
Contents |
Parameters
| key | - | key value of the element to search for |
| x | - | a value of any type that can be transparently compared with a key |
Return value
true if there is such an element, otherwise false .
Complexity
Logarithmic in the size of the container.
Example
Run this code
#include <iostream> #include <flat_set> int main() { std::flat_set<int> example{1, 2, 3, 4}; for (int x : {2, 5}) if (example.contains(x)) std::cout << x << ": Found\n"; else std::cout << x << ": Not found\n"; }
Output:
2: Found 5: Not found
See also
|
finds element with specific key
(public member function) |
|
|
returns the number of elements matching specific key
(public member function) |
|
|
returns range of elements matching a specific key
(public member function) |