C++ interview questions and answers

When one concrete type needs a completely different implementation than the primary template.

They accept a parameter pack of types or values.

Constructing an object in pre-allocated storage.

It provides a uniform interface over allocators with defaults.

noexcept tells the compiler the function will not throw.

Each entity should have essentially one definition across the program.

A non-owning view over contiguous elements with length.

Auto unpacking of pairs, tuples, and aggregates into named variables.

Many std::string implementations store short strings inside the object without heap.

Deleting a derived object through a base pointer needs a virtual destructor or you get UB.

co_await suspension points let you write async logic linearly with compiler-generated state machines.

Use atomic pointers with careful memory orders and ABA mitigation like tagged pointers or hazard pointers.

They synchronize producer writes with consumer reads without full sequential consistency.

They constrain templates with readable requirements so failures are earlier and clearer.

AddressSanitizer catches many cases in tests.

Bump allocation for many short-lived objects freed at once.

Prefer contiguous data, structure-of-arrays when scanning one field, and avoid pointer chasing.

It is a space-optimized specialization without real bool references.

Different CRTs and exception personality routines may not match.

Precompiled headers, fewer includes via forward declares, unity builds carefully, and caching like ccache.