C++: What is the difference between std::make_unique and std::make_shared?

Both create smart pointers, but with different implementations.

std::make_unique (C++14):

1auto ptr = std::make_unique<int>(10);
2auto arr = std::make_unique<int[]>(5);

std::make_shared (C++11):

1auto ptr = std::make_shared<int>(10);

Key differences:

1. Memory allocation:

• make_shared — single allocation (object + control block).
• make_unique — single allocation (just object).

2. Performance:

• make_shared — faster (one allocation).
• make_unique — standard allocation.

3. Custom deleters:

• make_shared — no custom deleters.
• shared_ptr constructor — supports custom deleters.

4. Array support:

• make_unique — supports arrays.
• make_shared — no array support (C++20 adds it).

Best practice:

• Always use make functions.
• Avoid new directly.