What is the difference between std::find and std::find_if?

Question

Accepted Answer

**find** — exact match. **find_if** — predicate match.

**std::find:**
- Finds exact value.
- Uses operator==.

```cpp
std::vector<int> v = {1, 2, 3, 4, 5};
auto it = std::find(v.begin(), v.end(), 3);
if (it != v.end()) {
    std::cout << "Found: " << *it << "
";
}
```

**std::find_if:**
- Finds with predicate.
- More flexible.

```cpp
// Find first even number
auto it = std::find_if(v.begin(), v.end(),
    [](int x) { return x % 2 == 0; }
);

// Find with struct
struct IsEven {
    bool operator()(int x) const {
        return x % 2 == 0;
    }
};
auto it2 = std::find_if(v.begin(), v.end(), IsEven());
```

**Variants:**
- `find_if_not` — negated predicate.
- `find_end` — find subsequence.
- `find_first_of` — find any of set.

C++: What is the difference between std::find and std::find_if?